More than a dozen traders and brokers in London and Asia have been fired, suspended or put on leave by their employers as part of a probe into the alleged manipulation of global lending rates, the Financial Times reported.
The newspaper, citing people familiar with the probe, said traders had been suspended, fired or placed on leave in recent months at Deutsche Bank (DBKGn.DE), JPMorgan Chase & Co (JPM.N), Royal Bank of Scotland (RBS.L) and Citigroup (C.N). All four banks declined to comment, it said.
Officials had also expanded their enquiries to both hedge funds that place big bets on movements in the rates, and the interdealer brokers that serve as go-betweens with the banks, the paper said.
It said Icap, the world's largest inter-dealer broker, had suspended one employee and put two more on administrative leave in the past six weeks.
Regulators since late 2010 have been investigating banks that help set interbank lending rates known as LIBOR and TIBOR in London and Tokyo, which are used to set interest rates on hundreds of trillions of dollars of securities.
Authorities are seeking to determine whether banks colluded to set overnight rates during the global financial crisis, and whether traders and their clients used the information to place profitable trades.
Icap declined to comment beyond saying said it was co-operating fully with authorities, the newspaper said.
Swiss authorities said last week they had received information about possible collusion between derivatives traders concerning LIBOR and TIBOR.
The Swiss Competition Commission said it was investigating 12 U.S., European and Japanese banks on suspicion of conspiring to manipulate interbank lending rates.
(Reporting by Richard Pullin; Editing by Kim Coghill)