Japan's Sankei Shimbun said in its Wednesday edition that Japanese defense authorities have confirmed that the vessel initially suspected of being a North Korean spy ship communicated with the North before being intercepted and sunk by Japanese patrol boats after an exchange of fire in the East China Sea Saturday. The authorities were able to confirm via information provided by the U.S. military that the trawler exchanged messages with the North before it was intercepted by patrol boats off the Japanese island of Amami Oshima. The U.S. forces stationed in Japan provided video information of the vessel after detecting it via a military reconnaissance satellite on Dec. 18th. The following day, Japanese defense officials were able to determine that the trawler was using the North Korean Workers' Party radio frequency.