Fearful that he was on the brink of revealing information about the sectarian murder of postman Daniel McColgan in 2002, Stephen McCullough was lured out on a lads' night out before being hurled to his death, our source says.
The body of McCullough (39) was found at the bottom of Cave Hill in north Belfast just a few weeks after the McColgan murder.
A low-level member of South East Antrim, he was believed to have fallen from the top of the hill and a subsequent inquest ruled his death an accident.
There have always been doubts surrounding his death and this week loyalist sources in Rathcoole in the north of the city claim he was murdered to keep him quiet. Despite these doubts, the police have categorically ruled out a murder.
And the man being held responsible is currently a senior figure of the organised crime gang and is a close associate of Brigadier Gary Fisher.
On the day of McCullough's death, he is believed to have approached an RIR soldier and told him he had information about the McColgan murder.
Daniel was shot up to 11 times as he turned up for work at a Royal Mail sorting offices in Rathcoole on the outskirts of north Belfast. His killers shot him several times as he lay face down on the road.
McCullough was detained by police on suspicion of drink driving but released without being questioned about the postman's death. Hours later he was dead.
According to our sources, there was concern about McCullough's mental state. He was prone to mood swings and is known to have been a heavy drinker who dabbled in drugs.
There is no evidence he was directly involved in the McColgan murder but had knowledge of who was. It is now understood he voiced his concerns about the killing to close friends.
It was enough to sign his death warrant, our source said.
The Rathcoole man was taken out by other members of SEA who then carried him to his death, our source claimed.
The Sunday World is aware of the identity of the leading figure involved. He has no convictions for serious crime but is known to be ruthless.
"He was terrified McCullough was going to squeal, so he shut him up," said our source.
Speaking at the time, Sinn Féin's Gerry Kelly said the circumstances of McCullough's death raised serious questions.
"Not least is why the RUC failed to act on the offer of information from a UDA member about the killing. It is also extremely worrying that this man ended up dead only hours after offering this information."
At his inquest a decade later, barrister Andrew Moriarty, representing the McColgan family, claimed material which had been disclosed for use at a forthcoming inquest suggested that Mr McCullough may have had information about the unsolved loyalist shooting.
He said: "We are armed with material which is suggestive that Mr McCullough was the type of person who may have had the information that he was purporting to have.
"There is a suggestion that he might have been killed." However, senior coroner John Leckey said there was no evidence of foul play in his death.
McCullough's death is not officially recognised as one of the multiple unsolved murders carried out by SEA, but the Sunday World has been told it is one of a number carried out by the members of Fisher's inner circle.
Last weekend the parents of a Catholic building worker questioned whether their son had been killed by an informant who was protected from prosecution.
Gary Moore (30), who was from Dungiven in Co Derry, was shot on a building site at Monkstown, Newtownabbey, in December 2000. No-one has ever been prosecuted for the father of two's murder.
The victim's parents, Marie and Nevin, are campaigning for a fresh inquest into their son's killing over concerns they were badly advised during the original in October 2002.
The family had been represented by the rogue solicitor Johnny Sandhu, who was later jailed for 10 years and struck off for inciting loyalist paramilitaries to commit murder.
UVF man Mark Quail had been gunned down at his Rathcoole apartment the previous month. Shot in front of his partner, he was the victim of a UDA/UVF feud, he is believed to have been the victim of another senior figure currently at the top of the SEA.