The Taoiseach has said he agrees with Justice Minister Michael McDowell's view that the Provisional IRA has been involved in criminality at Dublin Port.
Speaking to journalists, Mr Ahern said these issues must be a matter of serious concern.
When asked about Mr McDowell's view that some of the household names from Sinn Féin were on the IRA Army Council, Mr Ahern said he was not aware of this and that he personally did not know.
He also said he was not sure if the Minister for Justice was aware who was on the army council.
The Taoiseach said what was important now for unionism and the republican movement was to take the big step to save the peace process. He described next Thursday's meeting in Dublin with the British Prime Minister, Tony Blair, as crucial for the peace process.
Earlier, Sinn Féin's Chief Negotiator, Martin McGuinness, rejected claims by Mr McDowell that senior Sinn Féin members were on the IRA Army Council. He said Mr McDowell was wrong in his allegations.
He said the Minister was telling lies to stymie Sinn Féin's electoral growth on the island. He said the remarks by the Minister for Justice were ignorant and irrational and reflected his anti-working class and anti-republican agenda.
Mr McGuinness said the remarks were an unwarranted attack on republicans and were clearly driven by the approach of the European and local elections in the Republic.