HOW many more girls died at the hands of Fred West? No one will ever know, as he took that knowledge with him when he died in his prison cell.

The Gloucester builder himself claimed that there were 20 other victims about whom he had not told police.

That claim, which came in the final evidence given at the trial of his widow, fuelled speculation that the body count might be far higher than the 12 revealed by the inquiry sparked by the killings discovered at 25 Cromwell Street.

There is still a finger of suspicion pointing to a plot of ground in Glasgow once used by Fred West.

However, the only real possibility of a search by Strathclyde police at the site of his allotment in Gower street, Kinning Park, would arise if Rosemary West were to pass on the crucial information that her husband had boasted of earlier killings in Glasgow.

At the moment the only strand the police here have is the doubt voiced by Mr John McLachlan of Vallay Street, Milton - a man who provides a fascinating insight to Fred West's character immediately prior to his return to Gloucestershire.

In London, the National Missing Persons Helpline charity is now compiling details of girls still missing from that period to help police follow-up inquiries. But in the absence of hard evidence it is still likely that the final official death toll will remain at 12.

During more than 108 hours of tape-recorded interviews with detectives West admitted that he had killed 11 girls - but adamantly refused to admit that he murdered his pregnant girlfriend Anne McFall.

The tapes - some of which were played to the jury - clearly showed him to be a boastful liar who could not be relied on to tell the truth.

However, police are planning to renew their efforts to trace about 10 girls who still cannot be accounted for.

The mammoth and painstaking police investigation at 25 Cromwell Street traced around 200 young people who either stayed at, or visited, the house during two decades.

Police are now believed to be ready to launch a fresh appeal for information on the missing youngsters. They face a daunting task as in many cases they only have nicknames and vague descriptions to work on.

Detectives have also never closed the file on missing Gloucester cafe waitress Mary Bastholm - another girl Fred West claimed was one of his victims.

Fifteen-year-old Mary disappeared without trace from a Gloucester bus-stop while on her way to see her boyfriend in January 1968.

Gloucestershire police have so far declined to comment on any inquiries carried out by other police forces in connection with the Cromwell Street inquiry.

Only time, and fresh, hard evidence, will tell whether the fate of any more youngsters can be laid at the door of the Gloucester killer.

John McLachlan is one of the few people left in Glasgow with knowledge of the West case. He firmly believes that Fred's killing career did not begin in England. He knew West well, tangled with him in violent physical confrontation on a number of occasions, and was a lover of the murdered Rena Costello.

He vividly recalls first meeting her, a casual encounter at the house of a friend in McLellan Street, Kinning Park, which left him asking later: ``Who was that smasher?''

He can go back to the geographical locations, and to the actual people, involved in the tortured train of events which led Rosemary West to the dock.

His breathing now laboured by a serious heart condition, John McLachlan walks along McLellan Street where he lived in the early sixties and where he first laid eyes on Rena Costello - who was by then Rena West, having married Fred West in Ledbury in 1962 while pregnant with Charmaine.

The tenement where he lived, 94 McLellan Street, is gone, demolished to make way for the motorway, as is the tenement where Rena lived with Fred West - the end close in the street - and the bookie's shop next door where he first chatted up Rena.

Charmaine's father was an Asian bus driver, and this liaison, which would raise few eyebrows nowadays, led to Rena break with her family in Coatbridge and the move to Glasgow.

Both Rena and later Charmaine were destined to become victims, Rena the victim of Fred West at Much Marcle, the hapless child the victim of Fred and Rosemary West at Cromwell Street. Charmaine was last seen alive aged eight in 1971.

John McLachlan first saw Rena during a casual call at the home of a neighbour. Although a married man, he inquired who she was and was introduced. A few days later he met her as he went into the bookmaker's shop next door to Rena and Fred West's tenement and discovered there was a mutual attraction.

``It was obvious that even then Fred West was a violent man. Rena used to turn up with black eyes or bruises on her body that would make any man sick. Every time he gave Rena a doing like that I sought him out and gave him a doing. He was four inches bigger than me but I could use my fists,'' said Mr McLachlan.

``I remember giving him a very sore face after he struck the little lassie, Charmaine, for asking for a cone from his ice cream van. Any ordinary man would have given the child some ice cream but instead he smashed her round the head with his hand. I would not stand for that. It was obvious even than that he was a violent and sadistic bastard who enjoyed beating up women and kids.''

As the airport traffic thunders past where the McLellan Street tenements once stood, John McLachlan moves up a walkway alongside the concrete retaining walls of the motorway. This leads to a bridge - the original bridge - over the Paisley railway line and 200 yards on to Gover Street where Fred West had his allotment. Many of the original houses are still there, much as they were in the sixties, but the plots themselves are now occupied by good-quality, modern, private housing.

John McLachlan goes unerringly to the house which occupies the site of much of West's plot. A police officer who interviewed him early on in the inquiry showed him pictures of four young girls who had disappeared when West was in Glasgow. Mr McLachlan thought he recognised one of them and recalls that police told him they might eventually search any parts of the allotments which had not been built over using electronic equipment.

He said: ``We used to come up here every day. West had a piece of ground which was always well dug but which he never put any plants in. I asked him several times why he did not use that bit for potatoes and he always said he was keeping it for `special purposes'.

``I told the police this and said to them they should check up on missing girls from that period. I was told there were four, one of whose names - Margaret McAvoy - I recognised.

``Fred West sometimes did not return from the allotment until the early hours of the morning and I just wonder now what he was doing down there in the dark. A lot of the ground is still there, now back gardens. Some of the original trees are still there.

``I am not suggesting they disturb houses but I think the police should search the ground which remains open.''

Strathclyde police have had only the flimsiest connection with the West case. A senior detective told The Herald that they had been asked by an English force to speak to a number of relatives - principally of Rena Costello and Anna McFall - at the outset of the case almost two years ago. They had traced these people and taken statements to establish when Rena was last seen in Scotland.

John McLachlan's experiences would have formed part of the evidence against Fred West had he gone to trial. In the event, Rosemary West's defence team toyed with the idea of using Mr McLachlan had the need arisen to discredit further Fred's memory, but he was not called. His delicate medical condition, the result of open heart surgery, may have played a part in that decision.

He remains convinced, though, that Fred West was just as evil when he lived in Glasgow as he proved to be when he moved back to England - and that the police could do worse than to have a hard, close look at what remains of the Gower Street allotments in case the bones of young women lie there, 30 years on.

There has been at least one beneficial result from the black days of the West investigation. More than 100 missing girls and young women have been put back in touch with their relieved families in the aftermath of the Cromwell Street investigation.

Police have revealed the key role of the National Missing Persons Helpline, which aided the marathon task of identifying victims, some of whom were murdered 20 years ago.

The London-based national charity used its computer database to compile a list of 390 people whose ages, last known movements and dates of disappearance could be significant.

In just two months, the charity was able to make contact with 110 missing girls and pass on reassuring news to worried relatives.

It is now compiling details of girls who are still missing which could help police follow-up inquiries following Rosemary West's trial.

In an average week Helpline volunteers deal with about 500 missing persons calls, but such was the anxiety sparked by the Cromwell Street murders that inquiries tripled between February and April last year.

Spokeswoman Sophie Woodford said: ``We offer an independent, totally confidential point of contact, both for relatives and those who go missing for any reason. But it is a vast problem and we could do much more work if we had more funds.''

About 15% of those on the missing persons list are under 18 and there are three times as many girls as boys.

The charity, founded in 1989 by former Detective Superintendent Nick Carter, has 50 trained volunteers aided by a small full-time staff.

It also operates a Message Home - freephone 0500 700740 - for runaways who want to reassure their families that they are safe.