The body of a man, possibly a missing South Korean tourist, was found Tuesday morning on the premises of a security post branch of the Maritime Self Defense Force on Tsushima Island, Nagasaki Prefecture, according to a source and local police.

Nagasaki Prefectural Police are trying to confirm the identity of the man and investigating the cause of his death and whether foul play was involved.

While the motive remains unknown, the man's entry and his suspicious death may raise questions as to whether adequate security measures are in place at the Izuhara branch of the MSDF's Shimotsushima security post.

The MSDF unit on the island in Nagasaki Prefecture monitors the Tsushima Strait along the border with South Korea.

The island, located halfway between Kyushu and the Korean Peninsula also has a Ground Self-Defense Force unit stationed to engage in an initial response in the event of an armed guerrilla attack.

The body was found in a facility used to accommodate MSDF members staying over, according to the source and the police. No documents or firearms are stored there.

They said the body could belong to a South Korean man who visited the island on Friday on a trip with a friend and later disappeared. Police and firefighters have been searching for the man since a missing persons report was filed.