Bishop Edward Daly, the former Bishop of Derry, is denying that Father James Chesney was a mass murderer.
Chesney, a priest in a Derry parish in 1972, was named last week by the Northern Ireland police as the man who headed up an IRA unit that killed nine people in a bombing in Claudy in Derry in that year .
An eight-year-old girl and two teenagers were among the victims when three car bombs went off.
Chesney who was transferred after the bombings and died in 1980, was allegedly named by a fellow priest in a secret report as having confessed to him that he did the murders.
Reports last week stated that the British government and the police covered up for Chesney after being requested to by the Catholic Church.
Daly told the media that "Father Chesney vehemently denied involvement in any kind of IRA activity to me on two occasions, in 1974, not long after I was appointed Bishop of Derry, and again in 1977. He also denied such involvement earlier to my predecessor, Bishop Neil Farren," he said.
However Daly now says there was no cover-up. Writing in the Irish News, Daly who was Bishop from 1974 to 1993 stated : "Does anyone sincerely believe that if Cardinal Conway and my predecessor Bishop [Neil] Farren believed a mass murderer was in the Church's ranks they would have permitted him to continue in the active priesthood?
"I cannot believe they would have omitted to tell me when I was appointed as Bishop of Derry in 1974 if they had for a moment believed one of the priests in my future diocese was a mass murderer."
"Mass murder cannot be compared with any other sin or crime," he wrote "It is the foulest and most obscene of deeds."
"I witnessed mass murder at first hand in 1972," he recalled.(he was present at Bloody Sunday in 1972) "I am more aware than most of how appalling and grotesque it is and the enormity of it."
The bishop wrote , "It is a huge insult to suggest I would knowingly allow someone whom I knew to be a mass murderer to serve as a priest in my diocese."
Bishop Daly attacked the media coverage of the recent police report, stating that "the once sacrosanct presumption of innocence has been dispensed with and replaced with a presumption of guilt."
"Now, media portray as fact unsubstantiated claims emanating from agencies whose history is anything but clean," he noted.
The prelate said, "I find media coverage of the Claudy Report very disquieting."
He said that the press has put forth only "theories," and has "not questioned key aspects of the ombudsman's report."
The bishop asserted, "I am not at all convinced that Father Chesney was involved in the Claudy bombings."
The bishop said he had "constructive scepticism" about the allegations against the priest, as a result of "personal involvement in several major miscarriage of justice cases."
He continued: "I have seen convictions based on signed admissions and forensic evidence completely overturned years later.
"Father Chesney was never arrested, questioned, charged or convicted. He cannot answer for himself. He has been dead 30 years."
He noted that when he himself lived in South Derry during those years, "I was often terrified and humiliated by the treatment and delays I experienced at security force checkpoints as I returned from confirmations and other pastoral duties late at night."
He asked given this surveillance “ Why was the ombudsman unable to find evidence against him after years of investigation?"
He said "Claudy has at last received its legitimate and long overdue recognition as one of Northern Ireland's most despicable acts of terror."
He concluded, "I will continue to pray that 'the truth will out.' The families, the community and Father Chesney's relatives need to hear it."