Citi has fired a London trader in a probe over foreign exchange manipulation, the Wall Street Journal reports. Rohan Ramchandani, who was head of European spot trading, was put on paid leave in October but has now been terminated.

In November, the FT reported on Ramchandani’s role:

One specific chatroom, whose group was known alternately as the Mafia or the Cartel, was used by some of the most influential traders in London. Among them are Mr Usher, a former Royal Bank of Scotland trader who went to JPMorgan as head of spot foreign exchange trading in 2010, Mr Ramchandani, Citigroup’s head of European spot trading, Matt Gardiner, who recently joined Standard Chartered after working at UBS and Barclays, and Chris Ashton, head of voice spot trading at Barclays. All of these senior traders are on leave. Neither they, nor Mr O’Riordan, has been formally accused of any wrongdoing and none could be reached for comment.

Regulators are looking into allegations that traders might have used chat rooms to get a view about overall order flows and to use this information to build up positions just ahead of and during the fix. By buying and selling a currency before the fix, a trader can try to influence the final fix price to profit from the whole range of client orders he is handling that day