Police yesterday revealed that some months after nine people, including three children, were killed when three IRA car bombs exploded in Claudy, County Londonderry, in July 1972, the then secretary of state, Willie Whitelaw, and Cardinal William Conway, the Catholic Primate of All Ireland, discussed the attack and the priest’s suspected involvement.
The Police Service of Northern Ireland (PSNI) has not identified the priest, but he is believed to be Father James Chesney, who died in 1980. He was never questioned in connection with the attack which the IRA denied carrying out.
The claim, which came as relatives of the victims met police yesterday to discuss the outcome of a new investigation into the attack, sparked calls from the families and politicians for a full judicial inquiry, similar to the Bloody Sunday tribunal.
Ulster Unionist demands for an inquiry will be unrelenting, particularly with the Catholic Church at the centre of it.
The UUP leader, David Trimble, said last night: "Allegations of a cover-up need to be vigorously investigated.
"Any cover-up was, of course, a conspiracy to pervert the course of justice, and anyone who participated in a cover-up is culpable.
"There must be the same very visible searching and public examination as that which went into the Bloody Sunday Inquiry. Nothing else will do."
A government spokesman said all police inquiries would have to be finished before calls for a judicial probe could even be considered.
Assistant Chief Constable Sam Kinkaid said a search of 1972 papers clearly showed that a parish priest in south Londonderry was a Provisional IRA member actively involved in terrorism.
Mr Kinkaid added that inquiries had revealed that a member of the public, whom he did not name, briefed Cardinal Conway and a senior police officer on the priest’s role soon after the bombing.
His review team also discovered papers indicating that in late November 1972, the police briefed Northern Ireland Office officials on some of the priest’s alleged activities.
Mr Kinkaid said Mr Whitelaw and Cardinal Conway held a private meeting on 5 December, 1972, to discuss issues relating to the troubles. The following day, a briefing letter was sent from a senior NIO official to police headquarters which detailed some of the priest’s alleged activities.
By January 1973, police reports showed that the priest was not being seen in the south Londonderry area. Intelligence suggested he was working in Donegal.
The police ombudsman, Nuala O’Loan, last night confirmed she was investigating claims that officers failed to act on intelligence which may have been available at the time.
Fr Chesney was the curate in Cullion, one of the smallest parishes in County Londonderry. In the wake of the bombing, allegations began to surface that suggested he was an active member of the IRA’s South Derry brigade.
It was claimed that he had joined the republican movement in anger over the deaths at the Bloody Sunday civil rights march in January that year.
Earlier this year, 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.
Ivan Cooper, an MP for Mid-Derry, who suspected Fr Chesney was not all he seemed many years ago, recalled the young priest.
"He was in his late 30s, 6ft tall, dark and strikingly handsome, an extremely magnetic and engaging man. He was a familiar sight, haring along country roads in his sports car, and always managed to look sophisticated, even though he always wore his clerical garb."
Yesterday, the father of a nine-year-old girl killed in the bombing called on the former prime minister Sir Edward Heath and his defence secretary, Lord Carrington, to say what they knew about the attack.
Bill Eakin, whose daughter Kathryn was among the victims, said if there had been a cover-up he " would be very annoyed".
He added: "It is a strong possibility, but I can’t prove it. But I always felt why was nothing done? There seemed to be nothing happening at all.
"I call on those who were in authority to answer the questions raised by this investigation."
Mr Eakin said he was now more hopeful that the bombers were still alive, and would be brought to justice. "Why should they be walking around when we live our lives in a terrible state?"
Samuel Reilly, who lost part of his leg and suffered head injuries in the bombing, said: "It broke my heart today.
"Everybody in Claudy was innocent, got on the best, and they lost nine lives."
He too had confidence the police service would not let the matter drop, and the remaining bombers would be brought to court.
"I would like to see them get justice, those who were responsible for it. I would like to see them get life in jail for what they have done - they killed a wee girl of nine years old."