Fine Gael has warned that the Oireachtas Committee on Justice, Equality and Women's Rights may not have the powers to deal with the proposed report from Mr Justice Hamilton on the Dublin and Monaghan bombings.
The Taoiseach announced at the weekend that Mr Justice Hamilton, who is due to retire next month, would head an inquiry into the bombings. He will examine documents and then send a report to the committee.
Mr Ahern said the committee would have powers to send for papers and examine witnesses. The process was described as analogous to the report on DIRT prepared by the Comptroller and Auditor General for the Public Accounts Committee, which led to its examination of DIRT.
However, the Fine Gael spokesman on Northern Ireland affairs, Mr Charlie Flanagan, who is also a former chairman of this Oireachtas committee, said legislative change would be needed before the matter could be examined by it.
"The committee as it now stands may not have sufficient power to deal with these matters. In the first instance, the Oireachtas may have to enact new legislation which will allow the justice committee compel witnesses to attend and have appropriate documents, including Garda files, placed before it.
"Secondly, Section 5 of the Committees of the Houses of the Oireachtas Act 1997 must be amended to allow the committee deal with security-related matters."
He said the committee needed to be properly resourced.
Meanwhile, the Commissioner for Victims, Mr John Wilson, has welcomed the announcement that Mr Justice Hamilton is to head the inquiry. He was particularly pleased that the Government had acted on his recommendation that a retired Supreme Court judge should find the facts and assess them.
The Sinn Fein TD, Mr Caoimhghin O Caolain, gave a qualified welcome to the announcement. "When the Dail committee sits it needs to allow maximum access to those who wish to give evidence and to examine all aspects of this case. Now that this step has been taken a special focus is going to be necessary to ensure that the British authorities co-operate fully."