Stormont’s Finance Committee wants to call Mick Wallace and NAMA officials to appear before public hearings next week.
It is over Deputy Wallace’s claims in the Dáil that the proceeds of one of the agency’s sales were "earmarked" for a politician, and ended up in an Isle of Man bank account controlled by a Belfast solicitors’ firm.
The company has since said money was diverted to an account without its knowledge.
Sinn Féin Committee member Máirtín O Muilleoir says his colleagues should co-operate closely with the Dáil’s Public Accounts Committee as part of the probe.
He said it is crucial that NAMA officials take part in the hearings.
He said: "The feeling among the public is the first sum was paid in such a convoluted manner that the sales process was compromised.
"If NAMA was compromised then that's a total betrayal of the public."