Japanese authorities may have ignored UN sanctions last week when they released a vessel associated with Ocean Maritime Management (OMM), the North Korean shipping company behind the 2013 shipment of munitions through the Panama Canal.

The Hui Chon, which changed its name and associated management companies after being designated by the U.S. Department of Treasury last June, spent three days last week, starting March 9, in the Japanese port of Sakaiminato.

The vessel’s presence in a Japanese port may have contravened Japanese law, while its subsequent departure may have also been in breach of UN