On Tuesday, the Police Ombudsman for Northern Ireland will release his long awaited report into the Claudy bombing which killed nine people in July 1972.
No paramilitary group has ever claimed responsibility and no-one has ever been convicted of it, but for more that 30 years rumours have circulated that a Catholic priest, and the IRA brigade he was allegedly part of, were behind the attack.
When the investigation into Claudy was re-opened in 2002, part of its remit was to investigate claims that the British government, RUC and Catholic Church conspired to cover-up the activities of the priest.
Father James Chesney is no longer alive to talk about 31 July 1972 when three bombs tore apart the small village in the Sperrin Mountains, a few miles from Londonderry.
But when he died in 1980, he did so knowing that his name had been spoken of time and time again in relation to the bombing that killed people of both traditions, including an eight-year-old girl.
Fr Chesney was the curate in Cullion, one of the smallest parishes in County Londonderry, near to the village of Desertmartin.
It is an area of rural natural beauty, seemingly a world away from the violence of Belfast and Derry.
In the wake of the bombing, allegations began to surface that suggested Fr Chesney was an active member of the IRA's South Derry brigade.
It was claimed he had joined the republican movement in anger over the deaths at the Bloody Sunday civil rights march in January that year.
The then local Stormont SDLP MP and organiser of that march, Ivan Cooper, was among the first to hear the claims but did not have enough evidence to prove the suspicions.
Eventually rumours reached Fr Chesney's superiors within the church and he was called in for questioning by the then Bishop of Derry Neil Farren.
In an interview with the BBC's Sunday programme in 2002, Bishop Farren's successor, Edward Daly, told for the first time what happened.
"We spoke to him for a very long time certainly over an hour and we quizzed him very carefully about his position and was there any involvement with the IRA," he told the BBC.
"He denied that utterly, unequivocally, vehemently.
"He did say that he has republican sympathies, very strong republican sympathies.
"We decided that we'd appoint him as a curate in Malin Head, in the Irish Republic, in this diocese."
Former MP and civil rights campaigner Ivan Cooper knew Fr Chesney through his wealthy aunt and uncle Willie and Betty Noon.
Childless, the Noons treated Fr Chesney like a son.
Speaking to the Guardian newspaper in 2002, Mr Cooper recalled a "dark and strikingly handsome, an extremely magnetic and engaging man".
"He was a familiar sight, haring along the country roads in his sports car, and always managed to look sophisticated, even though he always wore his clerical garb," he said.
Rumours also circulated that his IRA activities affected many in his parish, when many of the social events he planned were robbed.
Many suspected the IRA, with Fr Chesney's help, was responsible.
The mystery letter
Father Chesney died in obscurity in 1980 - but perhaps not before he made a confession to another priest.
In 2002, a letter by a "Father Liam" arrived on several doormats in Northern Ireland.
It told of how a "Father John Chesney" from Northern Ireland had confessed his involvement in the IRA during a meeting with Fr Liam in Malin Head, County Donegal in 1972.
The discrepancy in the name has led some to question the authenticity of the letter.
Fr Liam, who has not been identified, said Fr Chesney gave him names of other IRA volunteers and details of the incidents in which he had taken part.
"We talked long into the evenings about the situation in the north and then, one evening, John broke down in a flood of tears and said he had a terrible story to tell," he reportedly wrote.
According to Fr Liam's letter, Fr Chesney was ordered to place bombs in Claudy to take the heat off the IRA Derry brigade which was suffering a new and sustained assault following the breakdown of the 1972 ceasefire.
Fr Chesney reportedly said they had wanted to leave phone warnings at nearby Dungiven, but could not find a working telephone box.
Later that year, the Police Service of Northern Ireland revealed that they believed a Catholic priest had been involved in the IRA in County Derry, but did not name him.
In a statement in December 2002, Assistant Chief Constable Sam Kinkaid said: "In a search of 1972 papers, information has been found which clearly indicates that a parish priest in the south Derry area was a member of the Provisional IRA and was actively involved in the Claudy bomb.
"Records show he provided an alibi for a person suspected of playing a prominent role in the atrocity. The priest is now deceased."
ACC Kinkaid also said his investigative team had found papers relating to a discussion held on 5 December 1972 between the then Northern Ireland Secretary William Whitelaw and Cardinal Conway, the then Archbishop of Armagh and Primate of All Ireland.
"This private discussion occurred at one of the regular meetings that they held to address issues relating to the troubles," he said.
"On 6 December 1972, the day after the meeting, a briefing letter was sent from a senior NIO official to Police Headquarters indicating that the private matter discussed related to the activities of the priest.
"The letter of 6 December 1972 indicates that the secretary of state gave the Cardinal a full account of his disgust at the priest's behaviour and also indicates that the Cardinal knew that the priest was behaving improperly."
No-one has ever been convicted of planting the three bombs in Claudy that day.
Relatives now wonder whether the Police Ombudsman's report will name the man who has been mentioned in connection with the atrocity time and time again.