A U.S. appeals court has upheld a lower court decision to fine three Chinese banks for refusing to comply with subpoenas in an investigation into alleged violation of North Korea sanctions. 

According to various news outlets, the U.S. Court of Appeals for the District of Columbia Circuit on Tuesday dismissed the appeals from the defendants, confirming a Washington D.C. federal court’s decision to hold the three banks in contempt. 

The banks have not been publicly identified, but are reportedly China’s Bank of Communications, China Merchants Bank and Shanghai Pudong Development Bank.  

According to reports, the U.S. Justice Department accused the banks of working with a Hong Kong-based firm, which allegedly laundered over $100 million for the North's Foreign Trade Bank.

The Washington Post said earlier that one of the banks, Shanghai Pudong Development Bank, is at risk of losing access to the U.S. financial system for its refusal to cooperate on related investigations under the U.S. Patriot Act.