The wife of Sean Dunne is asking a bankruptcy court in the US to quash subpoenas issued by the bad bank to various institutions, describing the moves as a "massive fishing expedition".
Developer Dunne is in the middle of protracted bankruptcy proceedings in Connecticut, where he filed for protection against creditors in March, listing debts of close to $1bn (€745m) and assets of less than $50m (€37m).
NAMA, through its subsidiary National Asset Loan Management (NALM), launched an adversary action against Mr Dunne, claiming he has been less than truthful, in filings and hearings, about his financial affairs.
It claims that Mr Dunne benefited financially from property transactions in the US and Switzerland, and that he used his wife and others to hide his involvement, which allegedly netted him millions of dollars.
But Eric Henzy, a lawyer for Ms Killilea, argued in a motion that, "NALM should not be allowed to use this adversary proceeding to conduct this type of fishing expedition for the purpose of later pursuing claims against Killilea."
The motion to block the subpoenas was filed on behalf of both Ms Killilea and Mountbrook USA, the Connecticut property development company of which she is principal.