By Jamie McGeever
LONDON (Reuters) - The U.S. Federal Reserve and Office of the Comptroller of the Currency have sent investigators to Citigroup's London headquarters as part of an international investigation into alleged manipulation of the global currency market, a source familiar with the matter told Reuters on Wednesday.
This comes after Citi last week fired its head of European spot foreign exchange trading Rohan Ramchandani, following a prolonged period on leave.
The Fed and OCC officials, who have been at Citi's Canary Wharf office in London this week, are at the preliminary stage of information-gathering and their presence is "independent" of Ramchandani's sacking, the source said.
The Federal Reserve and OCC, which is an independent bureau of the U.S. Treasury, both declined to comment.
A spokesman for Citigroup also declined to comment.
Last year, Britain's Financial Conduct Authority began a formal investigation into possible manipulation in the $5.3 trillion-a-day global FX market. The U.S. Justice Department is also engaged in an active investigation of possible manipulation of the market, the world's largest.
(Reporting by Jamie McGeever, additional reporting by Aruna Viswanatha, editing by Mike Dolan, Alex Smith and Jane Merriman)