There are a few things I won't talk about,'' says Edmund Ross emphatically, ''especially my son.'' But after a few hours his mood lightens slightly, as he lectures on the inequities of the still-unsolved murder case that propelled both he and Michael Ross, the son in question, into the spotlight. ''All I know is I'm innocent,'' he tells me, in the bar of the Orkney Hotel in Kirkwall, ''and my son is innocent. I never did anything wrong. Neither did Michael.''

Ross, who possesses a sense of bitterness that is both harsh and funny, is indignant. The former soldier and policeman was jailed in 1997 for perverting the course of justice following the murder of Shamsudden Mahmood in Orkney three years earlier. The waiter was shot in the head in the Indian restaurant where he worked, only streets from where we are now sitting.

At the time of the murder Ross's son, Michael, was 15 years old. He was later named in his father's court case as the prime suspect in the killing, something that still clearly frustrates and angers Edmund Ross.

A photograph at the time shows the youngster as an army cadet posing with his local unit, where he was a top marksman. Now, ten years later, he is a lance corporal with the Black Watch serving in Basra, Iraq. Ross shrugs. ''He was home recently for the birth of his second daughter,'' he says, gazing with intense eyes and the characteristic calm of an officer of the law. ''But now he's gone back.''

At the time the murder cast a dark shadow over Orkney, the people who lived there - and, in view of the ongoing nature of the murder, the competence of those who investigated such a heinous crime. Today, more than ten years later, a killer is still at large.

At first everyone though it was a joke. Restaurant manager Mahmood, known locally as Shamol, looked up and smiled a greeting. Then, as the man strode purposefully across the floor of the Mumutaz Tandoori, they thought it was a robbery. It was neither. The hooded figure walked over to 26-year-old Mahmood, who was serving a local businessman, his wife and their two children, before raising a handgun and pulling the trigger. After travelling through the Bangladeshi waiter's skull, a 9mm bullet lodged in the wall; an empty bullet casing lay on the carpet. It was a bright summer's evening on Thursday, June 2, 1994. The smell of newly mown hay mingled with the sounds and smells from the pier. The gunman walked calmly backwards, saying nothing, threatening no one else, before disappearing down a lane. Mahmood had been in Orkney for two months, having visited the island two years previously. He was

saving up to study for a law degree.

Within hours, detectives had arrived from Inverness and launched a murder investigation - the first in the Orkney islands in 25 years. They mounted a cordon at the airport and ferry terminals; armed police were on standby. There was no immediate suspect and no clear motive. Many of the islanders were in a panic, locking doors when there was never any need to in the past. One young girl kept her horse in the house because she was afraid it might be attacked. The local radio station replaced the usual slots on missing pets with murder inquiry updates. The murder had lodged itself like a wild bear on the island, and has refused to move since.

Despite more than 8,500 people being interviewed, and despite the help of Interpol, who were enlisted to track down foreign tourists, police were unable to discover anything substantial. The investigation moved to Bangladeshi communities in London and Southampton, where Mahmood had once lived. Police explored whether the killing could have been part of an ''ethnic feud'', drugs-related, a contract killing, or even a romantic liaison gone badly wrong. Witnesses stated that, a few days before the murder, two men were involved in an argument with Mahmood outside the restaurant, at midnight. Attempts to find them proved fruitless. A week after the killing it was reported that a woman received a death threat - ''Your life is at an end'' - on the night of the murder. Her number was similar to that of the Mumutaz restaurant. Although police never confirmed nor denied the warning call had happened,

it was believed that detectives leading the inquiry thought it was made to the wrong number.

There was also plenty of local gossip to stoke the rumour fires, and police suspected that, in a small place like Orkney, it would be difficult keeping secrets. The only real evidence, though, was the bullet casing ejected from the weapon.

It has been ten years since Mahmood's murder. Edmund Ross, 53, spent two of them in Porterfield Prison in Inverness, having being found guilty of perverting the course of justice and sentenced to four years. His face darkens. ''What did I do?'' he asks, and before I can answer he tells me: ''I was honest. I was sentenced for being honest.''

A decade ago, investigating officers tasked the then Constable Ross, an officer with the Northern Constabulary for 23 years, and who worked at Kirkwall police station, with examining the bullet that killed Mahmood. Possessing considerable firearms experience - he was president of the local gun club and a registered firearms instructor - Ross was a former Special Branch officer who had previously undertaken royal protection duties. He proceeded to test-fire all the 9mm weapons on the island, concluding that of the weapons he examined none was capable of firing the fatal bullet; neither could he find the same type of ammunition anywhere on the island.

In the mean time another line of inquiry presented itself. Days after the murder, a woman and her daughter told police that, a few weeks earlier, they had seen a man dressed in similar clothes to the killer, at one point wearing a balaclava, ''stalking'' from tree to tree in Papdale Woods. The significance of this would be revealed later.

On the day after the murder, says Ross, he was on duty outside the restaurant. ''One of the investigating officers that I used to work with in the CID in Inverness asked me to have a look in the restaurant,'' he says, his voice terse, much like any policeman guarding his information. ''I saw the empty case on the floor and the bullet in the wall.

''He asked me to look at them with 'your expertise'. I didn't touch the case, obviously, but had a look. There are four pieces of information on the base and I identified three immediately; the fourth I wasn't sure about. I looked at the bullet on the wall and that was it. I broke for lunch around one o'clock, spoke to my wife and told her what was going on. I got my reference books and checked for that particular type [of bullet]. Later I handed it over to one of two senior officers there, identifying where the round was manufactured: Kirkee Arsenal [a munitions factory] in India.'' He pauses, then says, ruefully: ''I have a great understanding of weapons and munitions but I'm not an expert. If you are classed as such, they think you know everything and it can sometimes go against you.''

As the enormity of what had happened sunk in, the days turned into weeks. Then the police received a breakthrough that was to turn the case on its head. On August 12, Ross, a former soldier with the Black Watch and the Royal Green Jackets who had served in Northern Ireland, informed colleagues he possessed a sealed box of bullets similar to the calibre and bearing similar numbers to those used by the killer in the murder. Ross insisted he could not remember where he had got them.

The man who supplied Ross with the bullets was James Spence, a former Royal Marine working as a labourer, and a former school friend. When police interviewed Spence he claimed to have given Ross two boxes - one from the Kirkee Arsenal, the other a box of .22 calibre bullets. Spence later claimed to have given Ross two boxes of 9mm Kirkee bullets, one sealed and the other open. He also claimed Ross had approached him on three occasions and asked him to lie to police about the bullets: a claim Ross now vehemently denies.

''Years earlier he [Spence] gave me a box of 9mm and two boxes of .22. One of the .22 was part-used. He was put under pressure by the police. Had I ever asked anyone to lie for me, which I never had done, I don't think Jim would have been the first one on my list. I said I didn't know where they were from because I didn't want to get him in any bother.''

Ross, who used to keep one key to his gun store around his neck and another one hidden, insists that if he had anything to hide he would have thrown the bullets in the sea and nobody would have been any the wiser. ''That particular batch of munitions was in a box I kept full of odds and ends. But I knew I wouldn't be using it. It's not good quality.'' He speaks softly but his manner is far from deferential. ''Bear in mind there was either 43 or 46 million rounds of that particular bullet made.'' The British Army had acquired roughly 45 million 9mm bullets in 1974, although the bulk were dumped in 1978 because they were of insufficiently high quality.

On September 8, 1994, the daughter of the woman who saw the man in Papdale woods believed she saw the same person in Kirkwall. Police used CCTV images to identify him as Michael Ross. Detectives questioned the teenager, who initially denied he had been in the woods - although he later admitted he had. His alibi for the night of the killing was later proven false.

Edmund Ross was suspended on full pay in March 1995. His fall from grace was compounded when, in May 1997, he was charged with wilful neglect and violation of duty by attempting to conceal evidence from officers during the investigation. He was alleged to have tried to hide evidence because he was afraid suspicion for the murder might fall on him, his relatives or his acquaintances.

Michael Ross was named in court as a suspect - and at the time had not, according to police, been eliminated from inquiries. But no charges were ever brought against him. Edmund Ross was found guilty and sentenced to four years. He resigned from the police force in May 1998 while inside. In June 1999 he was released, declaring his innocence of any involvement in the murder. Michael, meanwhile, was on his way to becoming a firearms instructor in the Black Watch.

Mahmood's death quickly became the stuff of headlines, before his story was discarded from the media as easily as his life. Exhaustive enquiries into his background revealed the same accounts from family, friends and employers; from a prosperous Bangladeshi family, he was decent and respectable. Although it was almost a decade before the Northern Constabulary admitted they believed the murder was racially motivated, it was, however belated, confirmation for the family of the dead man that their brother had been killed because of the colour of his skin.

Bulbul Shafiuddin, Mahmood's brother, is perched on the edge of a couch in the London home he keeps for his two daughters and wife, Ruby, while he works in Dhaka, Bangladesh, for most of the year. The failure to find Mahmood's killer, and the prosecution of Ross, has left lasting disquiet. ''When Mahmood was murdered,'' says Shafiuddin, 59, over tea, ''it was Ruby who was called to identify the body. I was away. She grew very depressed. She was frightened the killer might come to England for her and her daughters. She had a breakdown. The rest of the family [Mahmood was the youngest of seven brothers and four sisters], who were in Bangladesh, reacted badly also.'' Ten years on, Shafiuddin, a lawyer, cuts a similarly devastated figure.

He had originally brought Mahmood, an economics graduate, to England to study law, following the deaths of both parents. Mahmood had a girlfriend in Bangladesh, who was studying medicine, and the couple were planning to marry. ''But no one really knew they were together,'' says Shafiuddin. ''It wasn't socially acceptable. She was very young.'' He shrugs. ''She is married now.'' He pulls a thread from his shirt. ''Still there is nothing. This is not justice. And all we want is justice. I used to think that this country was a tolerant country. But my brother was killed in a racist crime and there is no guilty person. Why? And why did it take the police so long to admit it was a racist attack? If a policeman had been killed I am sure the killer would have been brought to justice now. There must be a cover-up.''

Once Edmund Ross was jailed, Shafiuddin believes, the heart went out of the investigation into the murderer, and the trail fell silent. He is calling for an inquiry into the failure of the prosecution service to convict anyone for the murder, in the hope that confidence in the justice system might be restored among minority communities. ''I definitely think there should be some kind of inquiry. But always at the back of my mind is whether there will be justice.''

I mention that Michael Ross is a soldier in Iraq and there is a long, long silence. ''He is a soldier?'' He looks at the carpet. ''I have not heard this before. I am shocked to hear that. I am very shocked. This young man was named as a suspect and he is working for the British government. How could they keep their eyes and ears shut?''

Shafiuddin talks a little longer. He came to England in 1967 from Bangladesh when Mahmood was only one month old. ''I did not see him again until he was about nine years old. He was a very good boy. Sometimes I feel I have not only lost a brother but a son as well. If I had never brought him here he would have remained alive today. It did not occur to me that I would have to bring his dead body home.'' Mahmood is buried in Bangladesh, where one of his younger brothers has started a scholarship in his name. ''I think the handling of this case has not been carried out properly by the Scottish judicial system or the police. This killing is my nightmare.''

According to family supporters, the inability to charge and find anyone guilty proves the Scottish justice system suffers from much of the same kind of institutional racism highlighted in the Macpherson report, which followed the inquiry into the murder of Stephen Lawrence in London in 1993; and indeed in the report into the handling of the 1998 murder of waiter Surjit Chhokar in Wishaw, North Lanarkshire. ''I want to see justice,'' says Shafiuddin finally. ''It's not because he is our brother but because it is in the greater interest of the country. It's not just about my brother, but justice itself.''

Edmund Ross is convinced that because people wanted answers to a difficult crime and the police were charged with providing them, his case was motivated by political expediency. He bemoans the fact they couldn't find the killer so they tried for the next best thing - a so-called bent cop. ''I know how this works,'' he says, briskly, ''I'm not stupid. I've seen so many things like this happen. Once the wheels are in motion you can't stop it even if you wanted to. During my trial one cop said I had, more or less, persuaded myself in to the scene of crime. Absolute no-no. No one enters unless they are invited in - the lowest cop or the Chief Constable. There was no way I would have walked in.

''The same cop indicated that I told him what bullet it was there and then, not later. If the jury accepted I knew from that moment what the bullet was, they had to accept everything else. When you throw all the other ingredients in, it is a beautiful broth. Yes, there are times when things are manipulated [by the police]. This was basically a beautiful broth.''

He points out that, as was revealed in court, there is no forensic evidence against his son and no link between Michael, himself and the murder victim. Nor has Michael Ross ever indicated that he took bullets or guns from his father's house. ''They knitted two things together [the bullets and Michael with the balaclava] and you have a beautiful stew. If you look at it from their point of view and the way it is presented in court, I would have found myself guilty.'' Shrugging, he jokes about how ''the family usually sit around polishing our Kalashnikovs''. He laughs easily and has a coruscating sense of humour but his repartee is wholly defensive. ''There were times, in the very early stages, when I questioned whether he [Michael] could have done it. I screamed and shouted at him and there was nothing that made me doubt my son. What brought him into the frame was the media. As far as

I'm concerned he's done nothing wrong.''

Previously I had talked to Kenny Pirie, a friend of the Ross family, who insists there is absolutely no connection between Michael Ross and the murder. ''All the connection they made was a name. There's nothing there. I know guys could do that in Glasgow and never blink. But there's no boy here who could do that and act normal for the next ten years. The guy that did that would do it again, and he would give himself away, talk in pubs, boast to pals, whatever. Michael was eight hours with professionals. Even his father said that if he had done it they would have broken him.''

Islander Norman Johnston claims that, the day before the shooting, he saw two men acting suspiciously down at the pier. They were in a Ford Orion car driving up and down the wrong way before one got out and stared up the street where the Mumutaz was situated. I catch up with Johnston, coxswain of Kirkwall's harbour tug, at the house he is building in nearby Stromness. ''The car had silver Hammerite paintwork,'' he recalls, ''very distinctive, a terrible paint job. One of them got out and kept looking up the street where the restaurant was. I went to the chip shop. He was still there when I came back. Tall, with a shaved head, tanned and wearing an army-type shirt. He was looking about, and then sat in the car and it drove away.''

When the police later released a photofit picture of a man seen outside the restaurant, Johnston was convinced it was the same person - a conviction he holds today. When he informed the police, he claims he was told the individual he described had been ruled out. ''But I knew who they were talking about,'' says Johnston, adamantly, ''an Icelandic fisherman, known to a number of islanders. It was not him.'' Johnston claims the police later denied he had been in touch with them. The car - or that man - was never found.

In the months following the killing, detectives detained Michael Ross for questioning. He was interviewed at least twice. Edmund Ross tells me he said to his wife, Moira: ''If he has done it, they will get it out of him.''

He says now: ''Both her and I, some neighbours and others were all at home, and then he was brought back. No lawyer, nothing. He was 16 at the time of the questioning. I was expecting something to happen. Nothing. I was screaming at him, 'Did you do it?' That was that. 'No,' he said.''

Half of Orkney feels it knows who killed Mahmood. Ross has been looking at his own son for ten years with the same question. ''Where is the proof? Why has Michael Ross not been charged with murder? I was looking at him as my son, but also the son of a policeman, and I genuinely never had an inclination either physically or emotionally to indicate he did it. Maybe I'm blind. I used to look at him and think to myself, if he did it he is either a psychopath or the coolest hitman in the world. If he did it he should be working for the mafia.''

I ask if his son will speak with me. He refuses. Why not? ''Because I know how the press twist things. So I've told him not to speak to them. He's got his own life to lead now. But he's got nothing to hide.'' A spokesperson for the British Army said: ''Michael Ross is innocent until proven guilty. The case in question had no bearing on him joining the army. He is a good soldier serving his country with distinction.''

So who killed Mahmood? And why? Ross sighs, studiously absorbed in his answer. ''In all honesty,'' he says, ''I don't want to talk or speculate about anything outside the sphere of my own family. I've got my wife and three kids to think about.'' Besides Michael, he has a 17-year-old daughter and another son, a commando in the Royal Marines. ''The pressure on the family was pretty immense. Quite honestly I haven't really thought about that aspect.''

In January this year, the current head of CID at Northern Constabulary, Detective Superintendent Gordon Urquhart, said publicly he believed the crime was a racist murder. In the months that have followed, little has changed. Senior Northern Constabulary officers believe they are simply lacking a few vital pieces of information that will convict the killer.

''There is no new evidence,'' DS Urquhart tells me. ''It's a bit of a stalemate of an inquiry at the moment. I don't think anybody had any idea at the beginning as to what kind of crime it was - and that was part of the difficulty of the investigation, that there was no obvious motive. It is only subsequent to this that we can determine it probably was a racist crime.''

Edmund Ross admits the inference in the media that he himself was a racist would have been partly rooted in his interest in Nazi history. ''I have a lot of books and literature on that. The police were searching at the scene [Ross's house] and came across this. People automatically assume 'racist'. I'm interested in all military history and in this case how such a small group could wield so much power.'' I ask if he is a racist. Engaging and straightforward, he looks at me with a bemused expression. ''You couldn't print what I think about the British National Party.''

Was his son influenced by many of the books Ross had in his home? ''Rabbit shooting, that was about the level of his politics. A racist? Rubbish. I don't think so. Michael never did much with books at all. I never talked to him about these things. It was reading material for my own consumption.''

Nursing an overwhelming sense of injustice and belief in his innocence, Edmund Ross adds: ''Look, I was convicted for a crime I did not commit. That's it. But unless you want to give me (pounds) 1m to take them on, what can I do? What did I do? I don't know what I did other than telling them about this ammunition.'' He looks away. ''I was angry then. It's passed now. People can make up their own minds. I'm 53 and I'm on the downward slope like everyone else. I get on with my life. Just understand this. I did nothing wrong.'' He drains his drink and leaves the bar. While his son's blossoming army career is seen in some quarters as dramatic irony in a case once described as a ''1,000-piece jigsaw'', Ross's new profession is equally incongruous. He is now an undertaker on the island.

The Mumutaz restaurant was sold and became the Eastern Spice a few years ago. Apart from some decorating it looks much the same as it did ten years before. Tonight the restaurant is quiet, winding down after a hectic summer season. I pick up a copy of the Orcadian, the local newspaper. Much heralded is the recently opened (pounds) 1.5m police station in Kirkwall - promising, somewhat ironically, to offer better public service. Iqbal, the restaurant's current owner, shows me the spot where the bullet pitched into the wall. Over coffee he insists that, in the four years since he has been here, there has been very little racism directed at him. A native of Bangladesh, he also owns a takeaway on the island and says that, apart from the occasional joke or shout, there is nothing for him to worry about. ''I wouldn't open a takeaway on the mainland,'' he says. ''There is too much trouble.''

He has heard a number of theories, many circulating within his own ethnic community, that Mahmood was shot as a result of gambling debts, that it was over drugs or that the wrong man was killed as a warning to someone else. He shrugs. ''I don't know. Who knows? It's a big mystery.'' When I speak with other islanders, few seem to feel at ease talking about the murder, as if it was something separate from themselves and from their luminous island. As if it belonged to the mainland, ''the place where this type of thing happens''. In Kirkwall they talk of Mahmood in whispers. They talk of his killer in equally silent tones.

While the murder of Shamsudden Mahmood is replete with ironies - a jailed former policeman protesting his innocence and his prime suspect son defending the nation in Iraq - perhaps the biggest irony is this: following the brutal slaying there has been only one other murder in Orkney. It was in May 2001, in a Kirkwall bedsit, not far from where Mahmood was shot. It took just five months from the time of the murder to find a suspect and deliver him to court, where he was found guilty and sentenced to life. Ten years and four months since a 9mm bullet was fired through the skull of a Bangladeshi waiter, the murder inquiry remains, tragically, open. n