The US Securities and Exchange has accused a pair of former head traders at Japanese bank Nomura of "deliberately lying" to customers in order to generate extra profits on the bank's commercial mortgage-backed securities desk in New York.

James Im and Kee Chan allegedly generated more than $750,000 in extra profits for the trading desk through fraudulent means, the SEC said on Monday. They traded commercial mortgage-backed securities, which are securities backed by commercial real estate loans.