US Federal Prosecutors are considering pressing charges against rogue trader John Rusnak over an alleged fraud at AIB, which led to the loss of €690m.
Authorities may use a law which makes it illegal to file false entries in the records of a bank with intent to injure or defraud.
The offence carries a penalty of 30 years in prison.
Mr Rusnak was a foreign currency trader at AIB’s American subsidiary, Allfirst, and is accused of carrying out a fraud over a five-year period.