Japanese authorities arrested a Chinese ship captain on Monday for not declaring a recent visit to a North Korean port, according to local media.

The captain’s detention was possible under Japan’s stricter autonomous sanctions on the DPRK, which prevent ships from entering Japanese ports if they visited North Korea within the previous six months.

The Palau-flagged Lucky Star 8 stopped at Japan’s Rumoi port in Hokkaido on March 27. According to Japanese authorities, the vessel falsely claimed to have visited a Chinese port between January 29 and February 1, when it was really in the DPRK’s eastern port of