Suspicions that the British authorities knew in advance about the Dublin and Monaghan bombings in 1974 would inevitably remain if the records of MI5 and MI6 were not made available to investigators, the Taoiseach said last night.
Mr Ahern said he agreed with Mr Justice Henry Barron that the scope of his report into the attacks was limited by the failure of the British government to make original intelligence records available to his inquiry.
The Taoiseach told a subcommittee of the Oireachtas Committee on Justice that a sworn public inquiry into the attacks was unlikely to secure access to such records. Such an inquiry would cost tens of millions of euro over several years, he said.
Without the co-operation of MI5 and MI6, it was unlikely to get the most relevant information.
Mr Ahern went on to say that the collusion investigations conducted by the retired Canadian judge, Peter Cory, merited examination by the sub-committee.
However, he had no information to suggest that the British government would co-operate. The greater likelihood was that the British side would say that it had co-operated in full with Mr Justice Barron.
Judge Cory investigated a number of high-profile murders in Northern Ireland where collusion between paramilitaries and the British or Irish security services was suspected. These included the case of the solicitor Pat Finucane, who was killed in 1989.
The Taoiseach said Judge Cory told him that he had "total access to an enormous amount of records" during this work.
Mr Ahern attributed this to the formal agreement between the Irish and British governments at the Weston Park talks in July 2001 at which the Cory investigations were agreed.
Still, Mr Ahern said that MI5 and MI6 were "almost impenetrable" and their records were unlikely to be revealed.
While he had no private knowledge of what was in the files, he said the security bodies would have made assessments about the circumstances of the attacks. "In my view we won't see those assessments, no matter what we do." Mr Ahern said he accepted that the Northern Secretary, Mr Paul Murphy, was telling the truth when he said that "all the potentially relevant information that had been uncovered had been shared with the inquiry".
The sub-committee is in the final stages of public hearings into the report into the bombings by Mr Justice Barron.
It will meet in public next week with Judge Cory before considering whether to recommend any further inquiry into the attacks on May 17th, in which 33 people were killed.
Mr Ahern's presentation was attended by members of the Justice for the Forgotten group.
