The cause of the death of a 30-year-old Cabinet Office official found in January in a rubber raft drifting off the coast of Kitakyushu was drowning, the Japan Coast Guard said Tuesday, ruling out foul play.
The man traveled to South Korea from the United States, where he had been sent to study at a graduate school, and bought the rubber raft and an outboard motor, the 7th Regional Coast Guard Headquarters confirmed.
"Out of his own will, he attempted to travel from South Korea to Japan by boat," the Coast Guard said in announcing the end of its investigation into the case. He was lost in the sea and an autopsy detected no drugs from the body, it said.
The Coast Guard said it has also gone through a notebook computer belonging to the man found in luggage left behind at a Seoul hotel and learned that he may have been on his way to visit a certain place in Japan. It did not identify where he was going and why, citing privacy.
The man had been studying at a graduate school in the United States since July last year, according to the Coast Guard and other sources. He traveled to South Korea on Jan. 3 to attend a seminar. He was found lying in the drifting rubber boat by a crew member of a ship sailing nearby on Jan. 18.