Taoiseach Enda Kenny has said that the Garda will investigate any fresh evidence that emerges with regard to historical atrocities, and that criminal investigations into them remain open.
His words in a letter to a Banbridge solicitor contradict a claim by former IRA director of intelligence Kieran Conway that historical cases were not being further progressed in the Republic.
Mr Conway, who now works as a solicitor in Dublin, had been quoting remarks by former Irish Justice Minister Michael McDowell.
Mr Conway has given several interviews recently after penning a book about his life entitled Southside Provisional: From Freedom Fighter To The Four Courts. His claims include an allegation that prominent members of the Irish establishment, including a leading banker, stockbroker, journalist and mainstream politicians, aided the Provisional IRA during the Troubles.
He also claimed the group's leadership received a tip-off from high-placed figures within the Garda that the force's Special Branch was planning to swoop on a meeting during a temporary ceasefire amid talks with Protestant clergymen.
Mr Conway said others helped move IRA weapons and money in top-of-the-range cars and provided safe houses for IRA members in some of Dublin's most affluent areas.
Banbridge solicitor John McBurney - who represented the family of murdered RUC Chief Superintendent Harry Breen during the Smithwick Tribunal's probes into claims of Garda-IRA collusion - has called for the Garda Commissioner to investigate claims made in the book.
The Smithwick Tribunal found that, on the balance of probabilities, there had been collusion between the IRA and a member or members of the Garda in the 1989 murder of Chief Supt Breen and Superintendent Bob Buchanan as they travelled back to Northern Ireland following a meeting at Dundalk Garda station.
In a letter to Mr McBurney, Mr Kenny said that in any cases which were not successfully resolved, the criminal investigations remain open and any new evidence which is brought to attention will be pursued by the Garda authorities.
Mr McBurney said: "I welcome the unequivocal statement by the Taoiseach.
"I trust the same position is being adopted by the Garda authorities and DPP. I would call upon the Garda Commissioner to investigate fully the revelations contained in Mr Conway's book and the various matters to which he refers in recent media interviews."
Story so far
Dublin solicitor Kieran Conway made a number of allegations in his book, Southside Provisional: From Freedom Fighter To The Four Courts. He claims prominent members of the Irish establishment, including a leading banker, stockbroker, journalist and mainstream politicians, aided the Provisionals during the Troubles.