Svetlana Kudryautsev, an associate who worked with London-based Lucy Edwards, another bank employee let go as a result of the investigation, was dismissed for failure to cooperate with the bank in its investigation of certain accounts, said a bank source.
US and international law enforcement officials, as well as the US Federal Reserve and the New York State Banking Department, are probing suspicions that Russian mobsters, senior government officials and businessmen pushed about $10bn from Russia, including proceeds of loans from the International Monetary Fund, through the US bank.
The IMF has said it has no evidence that IMF cash is caught up in a Russian money laundering scandal.
The Bank of New York, which has denied any wrongdoing and says it is cooperating with authorities, also put another employee, Natasha Gurfinkel Kagalovsky, on leave until the inquiry ends. Ms Kagalovsky was head of the bank's Eastern European division. Ms Edwards worked for Ms Kagalovsky in the bank's London office, while Ms Kudryautsev worked for her in New York.
None of the women has been accused of any crime, and Ms Edwards said though her lawyer in New York that she was innocent.
Meanwhile Barclays Bank found itself dragged into a separate Russian money-laundering scandal after it was reportedly named in an American lawsuit as an unwitting conduit for millions of dollars allegedly siphoned off from a minerals company. There is no suggestion that Barclays itself has been guilty of any wrongdoing and the bank denies allegations that it had been used to help launder money.