The man who leads the searches for the Disappeared has said it is a myth that the body of undercover soldier Captain Robert Nairac was put through a mincer after the IRA shot him dead.
Nairac was abducted after being attacked in the car park of the Three Steps Inn in Drumintee, Co Armagh. At the time of his abduction, he was armed but in plain clothes and was pretending to be 'Danny from Belfast'.
He was forced into a car, driven by a gang across the border and shot dead in a field.
By the time the murder scene was located by police, members of the IRA had removed his body. There has been no trace of his remains ever since.
Over the years, Nairac's activities have been the subject of much speculation, including rumours that he worked with loyalist terror gangs.
Last night, on RTE's Prime Time programme, Geoff Knupfer, the lead investigator with the Independent Commission for the Location of Victims' Remains (ICLVR), said he was convinced that Nairac's body could be found and dismissed the rumour it was put through a meat processor.
"It was a story put about by those personally involved," he added. "It was really about distracting attention from this area after the murder scene was found. We believe he is buried somewhere in north Co Louth."
There have never been any searches for the body because the commission does not know the precise location to examine.
Mr Knupfer described as "wild allegations" claims that Nairac was involved in a number of killings while active.
He told Prime Time that the ICLVR had investigated details of the soldier's military service and had not found "one shred of evidence" to support the allegations.
"We've tried to undertake a degree of research into his background because of these stories and really to find out if they were fact or fiction - we've done a lot of work on them," Mr Knupfer explained.
"We've not found a shred of evidence anywhere to support what are effectively wild allegations that he was involved in murder and mayhem and atrocities. He wasn't even in the island of Ireland when some of these events took place. And on other occasions he was elsewhere."
The programme also heard from a brother of IRA member John Francis Green, who was shot dead in a cross-border attack in Co Monaghan in 1975 that the Green family believe Nairac was involved with.
Leo Green, a former IRA member, said his family did not bear Nairac any ill will and called for the return of his body.
"My brother's death was not (properly) investigated North or South - there was a minimalist investigation," he said.
"We know in our heads and hearts what happened. We would like some acknowledgement by the British state of their role or not. That's what we are looking for.
"Although my family have a view that Robert Nairac was involved in my brother's death, there is no feeling of acrimony towards him and there is no feeling of acrimony towards his family.
"I have described him as a victim, in the same way that my brother was a victim.
"The Nairac family entitlement to truth and Robert Nairac's entitlement to a proper burial, his sibling's entitlement to give him that proper burial... it's up there with all the questions that IRA members' families have".