Renua leader Lucinda Creighton has called for the Banking Inquiry to be recalled to discuss "bombshell" allegations by the former IBRC chief Mike Aynsley.
Mr Aynsley told the inquiry last week he had been informed by one of his officials that Finance Minister Michael Noonan was prepared to take a €100m hit rather than sell IBRC loans to an unnamed Irish businessman.
The Sunday Independent last weekend revealed that Mr Aynsley was referring to telecoms tycoon Denis O'Brien, who was seeking to buy Topaz loans. Mr O'Brien subsequently bought the loans after IBRC's liquidation in February 2013.
Ms Creighton said: "Mike Aynsley dropped a bombshell before the Banking Inquiry last week. The inquiry has now gone on holidays and I don't think that's acceptable."
She added: "We need to hear from the Minister for Finance (and) from senior officials in that department as to precisely what instructions were given and precisely what happened.
"I don't think it's acceptable that Irish citizens have to wait now in excess of a month to hear any response."
Mr Aynsley told the Banking Inquiry last week that he was "shocked" when it was suggested to him that Mr Noonan would prefer to sell one of the bank's assets for €100m less, rather than offloading it to a certain businessman.
The claim was made in an email to Mr Aynsley from one of his staff, who was detailing a conversation he had with a Department of Finance official.
"The response from the official was that the lower price would be preferable and that he believed the Minister for Finance would be supportive of that position," Mr Aynsley said.
An Oireachtas spokesperson said there was currently no plans to recall the inquiry.