Fine Gael has described testimony by broadcaster Eamon Dunphy to the Mahon tribunal which appears to back up an allegation that property developer Owen O'Callaghan paid Bertie Ahern for political favours in the early 1990s as "dramatic and potentially damaging new information".
The party's Seanad justice spokesman Eugene Regan said: "This new information, as reported in the Daily Mail, further undermines the Taoiseach's already unbelievable explanation for the £300,000 worth of lodgements moving around his and his partner's accounts over a 20-month period in the early to mid 1990s."
Mr Regan said: "We now have a highly respected independent commentator and broadcaster, Eamon Dunphy, asserting that Owen O'Callaghan told him at a private dinner that he (Ahern) had been bought."
"The new information provided to the tribunal also describes events surrounding the provision of tax designation for the Golden Island site owned by Owen O'Callaghan on the last day of the outgoing Fianna Fail/Labour government in 1994," he said.
"Mr Dunphy described how the then Taoiseach Albert Reynolds had to 'hold a gun to his head' to get Mr Ahern to designate the site at Golden Island," he added.
A spokesman for the Taoiseach tonight declined to comment.