Former Anglo Irish Bank boss David Drumm has secured a legal agreement that effectively blocks gardai from gaining access to confidential documents, which are about to be revealed in the US.
The records are set to be disclosed during hearings related to Mr Drumm's bankruptcy case in Boston next month.
It is understood that Mr Drumm (44) has secured an agreement with Anglo that certain records about to be revealed cannot be used as part of any other proceedings.
The deal, which followed more than a month of negotiations, involved the bank agreeing with Mr Drumm the terms of a 'protective order', which prohibits Anglo from using the documents as part of any proceedings other than the American bankruptcy case against its former chief executive.
It also blocks the bank from handing over the documents to the Garda Fraud Squad or the Office of the Director of Corporate Enforcement (ODCE), which are investigating irregularities at Anglo during Mr Drumm's tenure.
It means that the ODCE would be forced to seek court orders of its own if it wanted to obtain the documents from Anglo.
However, there is no certainty that they would succeed if the material was destroyed after the bankruptcy action.
Under the terms of the agreement with Anglo, Mr Drumm can seek the immediate return of certain documents, or request that they be destroyed, once his bankruptcy case is concluded.
Mr Drumm fled to Massachusetts in December 2008, shortly before the bank's nationalisation, and has refused to return home to assist the garda and ODCE investigations.
The existence of the agreement was revealed in US court filings.
A judge is set to decide whether to approve the joint agreement in the coming days.
Mr Drumm filed for bankruptcy in Boston last October with €10.26m in debts, some €8.5m of which is owed to Anglo.
Lawyers for Anglo have requested a host of material ahead of planned questioning of Drumm next month.