Sinn Féin leader Gerry Adams has called for the establishment of a Commission of Investigation to examine what happened following the emergence of new allegations about the purchase of NAMA's Northern Ireland property portfolio.
He said Sinn Féin does not believe the taxpayer got the best value for money for the sale of the properties to a US vulture fund at a huge discount.
Ulster Unionist Party leader Mike Nesbitt is to ask the PSNI Chief Constable for an update on the investigation into the controversy, which is being carried out by the national crime agency.
Mr Nesbitt said a whiff of foul play will continue to haunt the body politic at Stormont until the full facts are known.
The UPP leader and Mr Adams issued their statements following new claims about the NAMA controversy made by a BBC Northern Ireland Spotlight programme.
The Spotlight investigation claims a businessman who had served on NAMA's Northern Ireland Advisory Committee was, at different times, in line for payments from prospective purchasers of the property portfolio and from some developers who were set to benefit from the portfolio sale.
The programme transmitted what is said were secret recordings of businessman Frank Cushnahan as he held discussions at a Belfast hotel.
It alleged that during those covert recordings Mr Cushnahan claimed he was to benefit financially from the sale of the portfolio to the eventual purchaser, US firm Cerberus, as well as being lined up for a payment from another bidder, PIMCO, until its bid was unsuccessful.
The programme also alleged that Mr Cushnahan claimed to have influenced a draft Memorandum of Understanding reached between the potential bidder, PIMCO and some DUP ministers in the Northern Ireland Executive.
The agreement would have protected developers from being pursued for personal guarantees they had given if PIMCO succeeded in purchasing the NAMA portfolio.
Department, NAMA to cooperate with investigation
The Department of Finance has said this is a matter for NAMA.
In a statement, the department said all relevant information that can be made public about the process has already been made public by it and by NAMA.
The statement adds that the allegations made in the BBC investigation repeat previous allegations relating to the buy side of the sales process and potential conflicts of interest of Mr Cushnahan.
There is no allegation of any wrongdoing directed against NAMA.
The department said NAMA and the Irish authorities will cooperate fully with any request for help made by the various investigating authorities.
The department is satisfied NAMA adhered to its mandate to achieve the best return for the Irish taxpayer.
This was clearly demonstrated through NAMA's insistence on an open market sales process for this portfolio which places each bidder on level footing in terms of their knowledge of the portfolio, the department said.
NAMA issued a statement this morning, saying it has dealt with the issue "very extensively over the past 12 months".
The statement says NAMA has nothing further to add at this time.