The British government has said that it gave "all relevent information" from its files to the Barron inquiry into the Dublin and Monaghan bombings in May 1974.
The assertion by the Minister of State for Northern Ireland, Ms Jane Kennedy, is in direct contrast with the conclusions of the report on the bombings by Mr Justice Barron, in which he said that the British authorities had failed to provide sufficient information to his inquiry.
In the Dáil yesterday the Taoiseach, Mr Ahern, said he did not believe the British authorities would be making any more information available to those investigating the bombings.
While Mr Ahern said that the British Prime Minister, Mr Blair, was not knowingly withholding files which he believed were needed, he did not think there was any way of securing records held by MI5 and MI6.
"Having watched the British dealing with a number of other inquiries and being familiar with the way the system works there, I do not think that there will be a change," Mr Ahern said.
"I have said in this House on many occasions that while I cannot guarantee 100 per cent co-operation in respect of the records held by the Northern Ireland Office and within the British defence system, the level of co-operation has been good . . . Records from MI5 and MI6 do not seem to be available as it has not been possible to get them."
Reponding to opposition questions about the disappearance of key Garda intelligence files from the Department of Justice, Mr Ahern said he had ordered an additional investigation into the disappearance.
The statement that the British government had provided all relevant information came from Ms Kennedy in a letter to Mr Caoimhghín Ó Caoláin TD.
He made them public as the judge was repeating his reservations about the response of the British authorities to the Oireachtas Joint Committee on Justice.
"The British government, as the Prime Minister and Secretary of State have made clear, has offered Mr Justice Barron's important inquiry as much assistance as possible," the letter said.
"I can assure you that all relevant information from our files has already been passed to Mr Justice Barron.
"His report refers to our need to withhold some original documents on security grounds and states that he fully understands the position taken by the government on these matters."
Ms Kennedy told Mr Ó Caoláin that the bombings of Dublin and Monaghan were a terrible tragedy "as were all terrorist atrocities committed on these islands".
Mr Ó Caoláin said the letter was "extraordinary". The judge said in his report that the British government had told the inquiry that some 68,000 files in the Northern Ireland Office were of possible relevance.
"Yet the Barron inquiry received only a 10-page letter from the British secretary of state in February 2002 and a similar follow-up letter," he said.