The Taoiseach said there is no "factual credence" behind claims the Government colluded with its British counterpart and loyalist paramilitaries in connection with the Dublin and Monaghan bombings.
Mr Ahern said he was aware of allegations made by a Sinn Fein Stormont Assembly member but added: "I have no evidence of anything untoward on these matters. Many things have been said over the years."
Today relatives of the victims of the bombings said politicians are "disturbingly ignorant" about the circumstances of the 1974 attacks which claimed 33 lives.
On May 17th, 1974, three car bombs exploded in Dublin city centre, killing 26 people and injuring more than 200.
Ninety minutes later, a car bomb in Monaghan killed seven and more than 40 were injured.
A spokesman for Justice for the Forgotten said: "It remains the single greatest loss of life in any one day of the Troubles and the biggest unsolved murder case in the history of the Irish state."
An independent private inquiry into the bombings has been established, initially under Mr Justice Liam Hamilton and then, following Mr Hamilton's death, Mr Justice Henry Barron, a former Supreme Court judge.
The Barron inquiry's report is to go before a public hearing of the parliamentary justice, equality and women's rights committee later this year.
Meanwhile, the Justice for the Forgotten campaign has sent 225 copies of a book called The Dublin and Monaghan Bombings to members of the Dáil and Seanad.
The spokesman added: "The campaign has decided to take this initiative because of the disturbing level of ignorance about the bombings and their aftermath by members of the Oireachtas."
Responding to questions in the Dáil, Mr Ahern said he had hoped to have the Barron report by now but promised it will be thorough.
PA