A former RUC officer convicted of murdering a Catholic shopkeeper refused to cooperate with Mr Justice Barron's investigation into the Dublin and Monaghan bombings.
News that Billy McCaughey declined to assist the probe came after the inquiry found that claims of collusion from his former colleague, ex-RUC sergeant John Weir, "must be treated with the utmost seriousness".
Both men, who were members of the RUC's Special Support group, were convicted of involvement in the 1977 sectarian murder of William Strathearn in Ahoghill.
The father-of-seven, who was well-known in GAA circles, was lured to his death in what became known as the Good Samaritan killing, by a UVF gang who called to his door claiming a child was sick and urgently needed attention.
Mr McCaughey, who was a long-serving member of the RUC at the time of the killing, was also convicted for his part in the bombing of a Keady pub, where he shot at a customer fleeing the scene.
The loyalist was also involved in the kidnapping of a Catholic priest from Ahoghillin 1978. He was released from prison in 1993.
Former RUC officer John Weir has claimed that members of the RUC and UDR colluded with paramilitaries in killings including the Dublin/Monaghan bombings.
Despite his murder conviction, the Barron inquiry found his claims to be "largely credible".
However, last night Mr McCaughey claimed Weir's allegations were "95% fiction".
The PUP representative, whose party is aligned to the UVF, also said the Barron team wrote to him over a year ago seeking assistance.
"About 75% of questions related to the matter solely within the jurisdiction of Northern Ireland," he said.
"On that basis I said no, I felt it wasn't their prerogative to investigate matters within the UK jurisdiction.
"They (the questions) were in relation to attacks, there were individual names. I was asked did I know them, did I know they were involved in x, y and z, that sort of thing.
"I was asked did I know senior officers in the alleged involvement in loyalist terrorism.
"Most of the stuff that they put to me was taken from a deposition which John Weir made to some section of the security forces down there (in the Republic). What Weir said was 95% fiction."
The loyalist said he "didn't know" if the security forces colluded in the Dublin/Monaghan bombings which killed 33 people and an unborn baby.
"I thought it was interesting they cleared the British government. The UVF, when they finally admitted involvement in it, said they carried it out on their own initiative," he said.
However, Mr McCaughey did give an insight into his own activities and how he obtained information while working as an RUC officer.
"Stuff I had involvement in I had no assistance from the government or senior officers," he said.
"My position is I was involved many, many years ago with the UVF before I joined the RUC."
