The leaked conversations, of executives at Anglo Irish mocking its rescue, has stoked anger across Ireland and Europe, tarnishing the country's image as an austerity success story just as it prepares to complete its bailout by the end of the year.
Ireland's central bank had worked with police looking into whether breaches of regulatory requirements had occurred after the Irish Independent newspaper published taped telephone conversations between executives of the now-defunct Anglo.
"No new issues have been identified that relate to suspected criminal offences having occurred and as a result the Central Bank does not intend - and is not required - to make any further statutory reports of suspected criminal offences," it said in a statement.
The tapes showed David Drumm, then-chief executive of Anglo Irish, saying he would demand "moolah" - slang for money - from the central bank.
Another executive was taped singing a pre-war verse of the German national anthem, as they discussed money flowing in from Germany after the government guaranteed the banks.
Bankers caught on the tapes apologised for the tone of the comments, but denied any wrongdoing.
The bank eventually cost taxpayers some €30 billion (£25.3bn) during the financial crisis, almost one-fifth of the country's annual output, and three former executives - not including Drumm - will go on trial next year on fraud charges.