Frank Hegarty was found shot dead by the side of an isolated border road near Castlederg, Co Tyrone, on May 25 1986. The 45-year-old's eyes had been taped shut and he had been shot several times before his body was dumped at the roadside by his IRA killers, who executed him because he was an informer.
The IRA claimed that Hegarty, who had been the organisation's Derry quartermaster, had revealed the location of a consignment of arms from Libya discovered by security forces in the Republic in January 1986.
He was afterwards taken to a safe house in England but, anxious to come back to his native Derry city, Hegarty returned to his Shantallow home that May after being assured he would not be killed.
On May 27 1986 the Irish News reported: "People who knew Frank Hegarty in Derry have confirmed that he was missing from his home following the arms find on January 26.
"He was a well known figure in the city and regularly associated with known republicans.
"At the time of his disappearance a number of people thought that he was about to become the latest republican supergrass.
"Most people who knew of his disappearance were baffled by his decision to return home to Derry three weeks ago, despite knowing that the IRA suspected that he had been involved in the Sligo and Roscommon arms find.
"It is felt that he must have been motivated by homesickness as he had been in almost daily contact with his family while in England and was known to be very close to his mother."
The IRA alleged that Hegarty had been responsible for a January 1974 Official IRA bomb attack at Ebrington barracks, Derry, in which two cleaners were killed.
The security forces used their knowledge of Hegarty's involvement in the bombing to coerce him into informing against the IRA, it claimed.
He worked first as a British army agent but was later recruited by the Force Research Unit (Fru).
Allegations that Derry Sinn Féin leader Martin McGuinness had played a role in persuading Hegarty to return to Derry were made by his mother in a 1993 edition of The Cook Report.
Mrs Hegarty said Mr McGuinness had assured her son that he would be safe.
During a House of Commons debate on December 18 2001, DUP leader Ian Paisley said that Hegarty had been "murdered on the instructions of Mr McGuinness".
Speaking during a debate on whether or not Sinn Féin MPs should be allowed to enjoy Parliamentary privileges, Mr Paisley said: "We have established that Martin McGuinness was, to all effects, leading the IRA army council and was busy in Londonderry.
"Members should know for what type of people they are proposing to bend the rules.
"One of the saddest calamities in Londonderry was the death of Frank Hegarty, who was murdered on the instructions of Mr McGuinness.
"Mr Hegarty had worked for military intelligence and knew where some of the IRA's most important arms and explosives were hidden in the Irish Republic.
"When the Irish police raided them the army, fearing that Mr Hegarty's cover would be blown, pushed him away to England.
"Mr McGuinness then arrived on the doorstep of Rose Hegarty and told her that he wanted to talk about her son and how he could return.
"Twice a week for 13 weeks, Mr McGuinness dropped by, the family met him and they drank tea together.
"He assured the mother, Rose, that if Frank came home, he could sort the matter out and all would be well; a firm assurance for a mother's heart torn about her son. She persuaded her boy to come home.
"A rendezvous was arranged by Mr McGuinness. Afterwards the body was found in a roadway in Tyrone, a bullet through the head."
Tapes allege McGuinness's IRA roleLast night's BBC Panorama programme restated the allegation that west Belfast builder Freddie Scappaticci was the British army agent known as Stakeknife.
It also presented evidence, in the form of transcripts made by journalists working on The Cook Report documentary programme, that Scappaticci had revealed the extent of Sinn Féin MP Martin McGuinness's involvement in the IRA.
"Nothing happens in the Northern Command that McGuinness doesn't OK – and I mean nothing," he is quoted as saying.
"You look at every British soldier shot, every policeman shot, every booby trap, or whatever.
"McGuinness is ultimately responsible for all of it. It's all under his control. He's the type of person you don't get side by side with.
"He doesn't have friends within the IRA. He has what he calls comrades. He frowns on womanising, he frowns on drinking... (he is) a very moralistic person."
The secret recording also details Scappaticci's view of the role played by Mr McGuinness in persuading IRA informer Frank Hegarty to return to Derry after he had told his British handlers the location of an IRA arms dump.
According to Scappaticci, Mr McGuinness befriended Mr Hegarty's mother after he fled the country in January 1986.
"He befriended her, as I understand it. He ate in the house, meals were prepared by the Hegarty family – basically Martin McGuinness sold himself to the Hegarty family," Scappaticci is quoted as saying.
"Martin portrayed himself as a friend: I'm someone who can deliver. Yes, you can trust the IRA, no harm will come to your son. He just has to come back and he just has to talk to a couple of people and he'll know one of them and everything will be fine."
Scappaticci claimed that Hegarty agreed to come and was driven to a secret location for an IRA debriefing, in which Mr McGuiness was part of the Army Council who interrogated him, "court martialled him and ordered him to be shot".
"It's not important who pulled the trigger. McGuinness wouldn't dirty his hands with that," Scappaticci said.
