North Korea detained three Japanese men on apparent drug smuggling charges in its special economic zone last month, but it later released one man, a news report said Wednesday.
The three Japanese employees of a machine maintenance firm in Tokyo visited the city of Rason, near North Korea's border with Russia, in March to check machines at a food manufacturing factory, Japan's Asahi Shimbun newspaper said, citing unidentified sources.
They were detained on charges that they hid drugs in canned goods to be exported to China, though the North later allowed one of them to return to Japan, the newspaper said.
The North has demanded a large bail for the two detainees, it said.
South Korea's Unification Ministry, which handles inter-Korean affairs in Seoul, and the pro-North Korean association in Tokyo said they had no information.
The North's state media have not reported on the case.
North Korea arrested a Japanese man on drug smuggling charges in 2003 before allowing him to return home on humanitarian grounds in 2009.
The news came days after North Korea confirmed the detention of a Korean-American man on a crime against the North.
The North said it will indict Jun Young-su, who was arrested in November, claiming he admitted his crime in the course of the investigation, the North's official Korean Central News Agency reported Thursday.