HSBC and Citigroup say they have suspended two traders each amid a global investigation into the alleged manipulation of currency markets.

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The banks confirmed the suspensions in statements Friday. HSBC’s traders work in foreign exchange in London, while the two at Citigroup worked in spot trading, one in New York and the other in London. Earlier last week, Deutsche Bank also suspended traders in relation to the probe.

HSBC said late last year that it is one of several banks being investigated for the possible rigging of foreign exchange markets. The other banks include Citigroup, JPMorgan Chase & Co., Barclays PLC, UBS AG and Deutsche Bank AG.

HSBC said in November that it was co-operating with the probe by British regulators.

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