Independents4Change TD Mick Wallace has called for a commission of investigation into the sale of NAMA’s controversial Northern Ireland portfolio, Project Eagle.
He said he is proposing a private members' motion to set up a commission and all the other countries involved in the sale had begun investigations into it.
Mr Wallace told the Dáil that the eventual buyer, Cerberus Capital Management, would double its money on the purchase, which he said would mean it got Project Eagle for half what it is worth.
He asked: "How are we not investigating that?"
Mr Wallace said the Public Accounts Committee's review of whether the State got value for money on the sale would not address the governance concerns.
Minister for Finance Michael Noonan defended NAMA's handling of the sale and said the agency had proven to be one of the great successes of Ireland’s economic recovery.
He said allegations of wrongdoing are extremely concerning and the UK had confirmed no aspect of NAMA's involvement was under investigation.
Mr Noonan said the appropriate investigations were taking place in the appropriate jurisdictions and advised against a costly commission of investigation.
Independents4Change TD Clare Daly said a commission of investigation would actually assist any criminal prosecutions and said the truth will out.
"'There is more dirt to come. You might think you have the numbers to get away with it, but it will come back to haunt you", she said.
Mr Noonan told Mr Daly that the notion of verdict first, trial afterwards was from "Alice in Wonderland".
Fianna Fáil has already said it would be proposing an amendment to the motion to allow for the criminal investigation into the sale to conclude.
Finance spokesperson Michael McGrath said the Public Accounts Committee must be allowed to examine the Comptroller and Auditor General's review.
In 2014 US Investment company, Cerberus Capital Management, bought the NAMA portfolio of Northern Ireland-based debtors.
It had a book value of £4.5bn. The purchase price was not disclosed but NAMA said at the time it was the biggest single transaction in the agency's history.
Mr McGrath said a commission of investigation was merited, but it would run into the sand while criminal investigations were under way.