The New York Times reports U.S. federal prosecutors may be investigating Japan’s largest financial group over alleged money-laundering for North Korea. 

The report says New York prosecutors subpoenaed an official of the Mitsubishi UFJ Financial Group late last year in connection with a legal fight between the Japanese bank and the New York Department of Financial Services. 

Authorities suspect the group intentionally ignored an internal filter that prevents dealings with sanctioned individuals, and failed to set up a system to avoid Chinese customers representing the North.

The state department fined the same bank twice in 2013 and 2014 for eliminating records of transaction with parties in countries, including Iran and Myanmar, or trying to hide information about it.