The former Labour leader made his comments as further questions were raised over recent claims by Taoiseach Enda Kenny the army could have been called in to protect ATMs in early 2012.
The Irish Examiner has also learned the banking inquiry is unlikely to accede to requests for Mr Kenny to tell the probe about being advised that soldiers should guard the banks.
The Taoiseach was this week accused of being a “spoofer” after he claimed that in 2012, former central bank governor Patrick Honohan told him the army might have to secure ATMs — a claim not supported by the ex-bank chief.
Mr Kenny told a conference in Spain the governor had told him during the eurozone crisis he may have to put the army around ATMs and introduce capital controls, similar to Cyprus.
But Mr Kenny this week admitted he received “no specific” briefing on this.
Mr Honohan has also refused to confirm or deny if he advised Mr Kenny about the army guarding ATMs.
Mr Rabbitte, meanwhile, yesterday told RTÉ’s Today with Sean O’Rourke security during the economic crisis was informally talked about by ministers.
“I know that for a prolonged period the future of the euro itself was at issue and I’ve no idea what the governor said or didn’t say to the Taoiseach.
“But I do know that a number of colleagues discussed the security dimension in my presence. I don’t recall it being discussed formally at cabinet.
“I remember 2012 as being a more serious year. I think 2012, in many ways, was the nadir of our crisis because during that time it did look like the euro was at risk.
“Our unemployment went to 15.1%. It was about the worst of all possible times and security was obviously an issue and security was being discussed.”
The former communications minister said he did accept Mr Kenny may be telling the truth.
Fianna Fáil has questioned the veracity of Mr Kenny’s comments and called on him to make a full statement in the Dáil.
Sinn Féin has accused Mr Kenny of being a “spoofer” and of telling “tall tales” on an international stage, while also demanding that he clarify the issue with the banking inquiry after failing to raise the issue in evidence.