A LOYALIST terrorist stabbed to death in Glasgow's east end is at the centre of a major police inquiry into collusion between the British state and protestant paramilitary gangs in Northern Ireland.

Lindsay Robb, who lived in Scotland after his release from prison, was killed a year ago today following a row in the street. He was knifed 22 times.

Brian Tollett, a former soldier, was found guilty of killing Robb and sentenced to seven years in jail.

Robb was a controversial figure in Northern Ireland. A gun-runner, a terrorist, a Nazi sympathiser, a man who took part in peace deal negotiations, and an agent for both MI5 and Special Branch - Robb, 38, was rarely out of the spotlight. Now, even in death, he still attracts controversy and intrigue.

The investigation in Northern Ireland into Robb's activities stems from a confession he made to the Sunday Herald back in 2000. Robb had then claimed that the RUC colluded with loyalist murder gangs to jail a high-ranking republican activist thought to be an IRA hitman.

Investigators from the office of the Northern Ireland police ombudsman - given the task of investigating allegations of collusion between the police and paramilitaries during the Troubles - came to Scotland this month to interview Sunday Herald staff who knew Robb as part of their inquiry.

Robb had claimed RUC Special Branch officers made a deal with loyalist terrorists to send prominent Republican activist Colin Duffy to prison for the assassination of an ex-soldier in 1993.

Robb told the Sunday Herald in February 2000 that he gave evidence in court putting Duffy at the scene of the assassination of John Lyness in Lurgan - Robb's home town - following a plot hatched between the RUC and the Ulster Volunteer Force (UVF), the outlawed loyalist terror group.

Robb said RUC officers approached the UVF after the IRA murder and asked them to supply a witness implicating Duffy. At the time, Robb's claims re-ignited anger and allegations of a "dirty war" undertaken by the British security forces in their fight against the IRA.

After Duffy was jailed for life, Robb was given a personal protection weapon and £2000 "by way of a thank-you from the RUC". Robb relocated to Scotland but was jailed for gun-running in 1995. As a result, Duffy's conviction was quashed as the evidence against him was no longer considered credible, and he walked free from the appeal court.

A year later, Duffy was accused of murdering two policemen. The charges were subsequently dropped.

The UVF had previously tried to kill Duffy in an ambush attack in the north of Ireland. After Robb confessed to colluding with the RUC, Duffy went on record saying: "I have always suspected there was some element of collusion in Robb's evidence against me.

"We are looking at the police fabricating evidence against me."

Republican leaders said Robb's confession was "historic" as it was the first time a loyalist paramilitary had provided, in his own words, proof of collusion with the British state.

The RUC has always refused to confirm or deny any allegations that Special Branch officers struck a deal with loyalist terrorists or that Robb received a £2000 "thank-you" for his assistance.

However, sources in the police ombudsman's office in Belfast say they are "pretty convinced" the confession Robb made to the Sunday Herald in 2000 was "genuine and stands up to scrutiny".

Senior UVF sources have also confirmed the "Robb deal" was indeed struck between the RUC and the UVF "to get rid of" Duffy. According to the UVF, the organisation had tried to kill Duffy a number of times, but failed. Duffy was also subjected to intensive RUC and British Army intelligence surveillance.

One former UVF commander said: "The implication from the RUC was that if we did this for them, they would go easy on investigating any UVF operations by the mid-Ulster unit the UVF cell operating in the Lurgan area."

Sinn Fein has been pressing for a thorough investigation into the allegations made by Robb to the Sunday Herald.

At the time of his confession, Robb said: "My evidence against Duffy was part of a deal struck with loyalist terrorists - namely the UVF - and the RUC."

He insisted his evidence was not perjured, but added that he would never have come forward as a witness "without the request of the UVF following approaches made by the RUC".

He stated categorically, however, that he believed "the RUC colluded with the UVF to get rid of Duffy".

Robb said he told the police: "I wasn't going to do this for nothing, and that's why I was given the gun and the money."

After making his confession, Robb became an increasingly pathetic figure. He was cut adrift from the loyalist community in Northern Ireland and haunted the fringes of Scotland's underworld. Money became increasingly tight for Robb and there were allegations that he became involved in drug dealing.

One loyalist source, when told this week about the investigation into Robb's collusion claims finally materialising, said: "The man was a curse - both alive and dead."