The Taoiseach, Mr Ahern, has stood by his claim that the president of Sinn Féin, Mr Gerry Adams, was a member of the Provisional IRA, although he has expressed confusion about why Mr Adams has issued repeated denials in recent days.
However, Mr Ahern insisted that he "didn't really care" whether Mr Adams had been a member of the terrorist group. "What I am more interested in is the future," he told journalists in Dublin.
"I don't want to continue on the argument. I made a comment in answer to a question and he said that it wasn't true. He is in my view not being consistent with what he said previously, but that is a pressing matter for him."
Mr Adams, he said, had made in the past comments "on the public record".
"I went back and looked at the references that I looked at previously and I don't think that I misinterpreted the references. It is on the public record what he said on previous occasions. I will take him on face value. If he said he wasn't, then he wasn't. I have a different understanding," the Taoiseach went on.
Denying that his relations with Mr Adams are strained, Mr Ahern said both Sinn Féin and the Government are "dealing with a peace process".
"We are trying to make substantial progress on the way ahead. I don't really care if he was or he wasn't a member of a particular organisation. What I am more interested in is the future. I am more interested in getting on with the future."
He sharply rejected Sinn Féin's repeated charge over the weekend that his remarks were intended to hurt the party's chances in the upcoming local elections in June.
"It's nothing to do with electioneering. It's nothing to do with anything else. The factual position is that we are back at the review. We have enormously important work to do and we have to get on with that."
Questioned again, Mr Ahern indicated that his statement that Mr Adams was involved in the IRA in the past is based on books written about the Troubles, rather than any security briefings.
"I always understood that he was a member and I had read that he was a member. I read quotes previously that I thought were references. I can show the reference and I went back to look at them.
"Now he says that this isn't true, that confuses me and I have to deal with the bigger peace process and get on with it. I went back at the weekend when I had the chance to jog my memory and my own personal library.
"I am not basing this on security information. I am basing it on his own reference and his own reference when you look at it indicates that he was, and perhaps I could give him the reference because he thought that I was being unhelpful coming into his ardfheis.
"In practice his own reference indicates that he was. Maybe he forgot that he made that reference. That is why I don't know why he said he wasn't. I don't want to call anyone guilty by mistruths. I will show him his own references, and then he can say that he doesn't recall the reference," Mr Ahern said.