Three men have been arrested in London in connection with an ongoing investigation into the manipulation of LIBOR rates, according to a statement from Britain's Serious Fraud Office. All three men are British nationals and are residents in the country, the SFO said. It did not name the arrested parties.

Reuters, citing sources "familiar with the situation" whom it did not identify, named the three as Terry Farr, James Gilmour, and Thomas Hayes. The first two men worked at interdealer broker RP Martin, according to one of Reuters' sources. According to another source, Hayes was formerly a trader at Citigroup (NYSE:C) and UBS (NYSE:UBS).

These are the first arrests in a sprawling multinational and multiagency investigation into LIBOR fixing. The SFO is one of many organizations investigating people and companies connected with such activity.