It is claimed a NAMA official has admitted leaking classified information to overseas financiers.
The Irish Independent reported this morning that the Garda Fraud Squad is studying documents, after the former employee admitted giving sensitive information to a named individual who should not have received it.
A dossier is currently with the Garda Commissioner Martin Callinan.
The National Asset Management Agency has refused to comment.
Independent TD Stephen Donnelly said the public need to be sure NAMA is not leaking anything in an improper way, and it should be "above reproach".
"There are emerging allegations, they're very serious … I hope that none of them are true.
"NAMA must be above reproach. Therefore, it may be necessary to have an independent inquiry to investigate these issues," he said.
Minister Michael Noonan later confirmed that an investiation is under way, and urged anyone with information about alleged wrongdoing to come forward.
"Under section 19 of the criminal justice act, they're obliged under pain of penal sanction to provide that new information to the Garda Síochána, and I'd advicse them to do so," he said.