A close friend of a man murdered by the IRA in Long Kesh has been offered a joint meeting with Gerry Adams and an IRA Army Council representative to discuss the controversial death.

Paddy Joe Crawford (22) was found hanging from a rope in a wooden hut in the prison in 1973. He was killed for passing information to the RUC during interrogation in Castlereagh. His death was made to look like suicide.

Gerry Adams has been accused of ordering his murder by Brendan Hughes, a former senior Provisional, in Hughes' memoirs, Voices from the Grave, published earlier this year.

Gerry McCann, a childhood friend of Crawford's, is asking Sinn Féin and the IRA to come clean about the murder. Adams has already had three meetings with McCann – the last as recently as 10 days ago – in which he claims no knowledge of IRA involvement in the death.

McCann has also held discussions with senior IRA man, Bobby Storey, and has had two meetings with the IRA Army Council representative. He is asking the IRA to admit it murdered Crawford and to apologise.

He has been offered the joint meeting with Adams and the Army Council member later this month. "I hope it will bring a result," he says. "I know Paddy Joe was murdered. I've no political agenda; all I want is the truth." McCann is also asking the North's new attorney general, John Larkin, to reopen the inquest.

Crawford, who had been in cage five of Long Kesh, was found hanging from a rope in a prison workshop. Raised in an orphanage, he was a soft target to murder because he had no family to ask questions.

But the Sunday Tribune can reveal that he wasn't an orphan ? he was from a well-known republican family. His half-sister, IRA member Anne-Marie Pettigrew, was killed just three months after Crawford's death when the bomb she was handling exploded prematurely.

Meanwhile, a republican source, who was in prison at the time, has given the Sunday Tribune details of the murder and has named the three men he claims killed Crawford.

The republican says: "When being debriefed by IRA intelligence officers in jail, Crawford admitted what he'd done in Castlereagh. They reported back to the Belfast Brigade OC. There was no court of inquiry or court martial in keeping with the [IRA] green book. The decision was made to take him out. It wasn't an execution, it was murder."

According to the republican, the three prisoners ordered to kill Crawford were Harry Burns from West Belfast; Thomas 'Tucker' Kane from the Falls, one of the 'magnificent seven' who had escaped from the prison ship, the Maidstone; and Jim McCormick from the Markets in south Belfast.

Two years ago, McCormick's son Jim was acquitted of charges connected to Robert McCartney's killing. After Crawford's murder, his killers initiated a cover-up. Burns was the only prisoner allowed to make a statement to the authorities. He falsely claimed Crawford had been depressed and acting irrationally.

Burns made his statement as "cage five OC", which gave it weight. However, the Sunday Tribune can reveal he didn't hold that position. The OC was another prisoner, Paddy Joe Rice.

The prison authorities and police knew this but effectively colluded with the cover-up.