A former papal nuncio to Ireland maintained a close relationship with senior Provisional IRA figures and lobbied the Irish government on their behalf throughout the 1970s and 80s.
Sean Donlon, the retired Secretary General of the Republic's Department of Foreign Affairs, has revealed that Taoisigh Jack Lynch, Liam Cosgrave and Garret FitzGerald "had problems" with Archbishop Gaetano Alibrandi's "close relationship with prominent Provos".
The former Irish Ambassador to Washington said of the Sicilian prelate: "For a man who spent 20 years in Ireland, he seemed to pick up little feeling for what was happening."
Speaking to the Irish Independent, Mr Donlon also suggested there were priests in the Irish church "who had some feeling the Provos had a justification for what they were doing".
"It is a matter of public knowledge that there were a small number of priests in Northern Ireland who were probably even involved with the IRA", he said.
Ireland's most senior retired diplomat also said the Irish government was concerned in 1987 when it learnt of substantial quantities of money in several accounts belonging the papal nuncio and considered declaring him persona non grata.
Mr Donlon said "informal representations" had already been made by the State to the Holy See about transferring the archbishop before it emerged that the "significant amounts of money" in his bank accounts had not been declared for tax.
"The amounts involved were far greater than would have been needed to run the nunciature," he said.
Archbishop Alibrandi was questioned by Department of Foreign Affairs officials and "claimed diplomatic immunity on the accounts" meaning they were not liable for DIRT tax.
He was warned that if he was claiming the accounts belonged to the Holy See this would be verified with the Vatican. The nuncio then claimed the money belonged to his brother.
"Clearly that was not a particularly satisfactory explanation," said Mr Donlon.
It was then agreed the nuncio would close the accounts, transfer the money and retire from his post in Dublin, otherwise "the state could have declared him persona non grata".
Mr Donlon suggested the Alibrandi episode was one of the reasons why "insiders would not have been surprised" by Taoiseach Enda Kenny's speech in the Dail in July last year in which he was critical of the Vatican, as the Fine Gael leader would have been broadly aware of the difficulties successive Irish Governments had had over 25 to 30 years with the Holy See.
Mr Donlon was speaking to the Irish Independent following the Garret FitzGerald Memorial Lecture which he gave last week at University College Cork.