Media Speculation suggests that the FR is the lead agency for an inquiry into a potentially huge irregularity in the books of a London-based trader working for Merrill Lynch.
The probe relates to trades at the London office of Merrill Lynch International Bank, which is registered in Dublin and also has offices in Geneva and New York.
Under international regulatory rules, the Irish regulator has responsibility for the inquiry as the company the trader worked for is Irish-registered. The FR is working with the Financial Services Authority (FSA) in London and authorities in the US. Merrill Lynch is owned by the Bank of America.
Media speculation suggests the trader had been suspended after accumulating more than £284 million (€316 million) in undisclosed losses in recent months. The Irish regulator was informed in February that there may be a problem with the company.