A trio of former City of London traders are to be charged by American prosecutors as part of a long-running probe into rigging the $5.3 trillion (NZ$7.5b) a day foreign exchange market.
It is understood the US Department of Justice is poised to bring criminal charges against the three - who were part of an online chat room called "The Cartel" which is alleged to have been used to manipulate foreign exchange - alleging they sought to manipulate the price of US dollars and euros in the currency market.
The three men are Chris Ashton, who was formerly global head of spot trading at Barclays, ex-JP Morgan dealer Richard Usher, and Rohan Ramchandani, formerly of Citigroup. Matt Gardiner, another member of "The Cartel" who used to work for Swiss bank UBS, has been helping the DoJ.
Given the trio are based in Britain, they will either have to go to the US voluntarily or American authorities will have to seek to extradite them.
The charges are expected to be filed in New York.