Mr Justice Barron last night delivered his report to the Taoiseach on the 1974 Dublin and Monaghan bombings in which 34 lives were lost.
While Mr Ahern said last night he would bring the report to the Government as soon as possible, publication is not expected for a number of weeks.
The report was originally expected a year ago. Mr Justice Barron's work was frustrated by a lack of co-operation from the British authorities.
Mr Ahern said last night that the Departments of Justice and Foreign Affairs and the Attorney General, Mr Rory Brady, would examine the report before it would be passed to the Joint Oireachtas Committee on Justice for publication.
He thanked Mr Justice Barron and his team for their work and praised their commitment and dedication to "this difficult task".
He also paid tribute to the earlier work of the former Chief Justice, the late Liam Hamilton, who took initial charge of the inquiry in January 2000.
Describing the attacks as "among the most appalling outrages in the history of this island", Mr Ahern said he had given a commitment to the Justice for the Forgotten group to ensure that the truth was established "in relation to the bombings and their aftermath".
The Barron report addresses persistent allegations that members of the British security forces colluded with the UVF bombers who plotted the attacks on May 17th, 1974. The Dublin bombs in Parnell Street, Talbot Street and South Leinster Street killed 26 people, one of them a pregnant woman.
The Monaghan bomb killed seven people; some 240 people received hospital treatment.
Mr Ahern said: "Not only were 34 innocent lives lost on that terrible day but the injured, relatives and friends were left a terrible legacy of pain and suffering."
With the case remaining the biggest unsolved crime since the establishment of the State, it also examines the nature, extent and adequacy of the Garda investigation.
Mr Justice Barron was specifically asked to examine why there was no prosecution. He was asked to examine whether the investigations were impeded and if so by whom. He was also asked to examine the extent of co-operation with the Northern Ireland authorities, the handling of evidence and the scientific analysis of forensic evidence.
While no information on the conclusions of the report was available last night, Mr Ahern has alluded in recent months to difficulties encountered by the British government in acquiring data. He told the Dáil last June that the delays in the publication of the report could be attributed to the specific nature of the deliberations and the difficulties encountered by the British government in acquiring data.
The Government had done everything it could to deal with the issue, Mr Ahern said. It would be "over-optimistic" to say that the judge had received all the information he wanted.
Mr Justice Barron is expected to produce a separate report into the Dublin bombings of 1972 and 1973 in the coming weeks. A further report is expected in the new year into the Dundalk bombing and the murder in 1976 of the Dundalk man, Mr Seamus Ludlow, which is believed to have been carried out by UDR members.
