A man linked to the Red Army Faction who had been living in Pyongyang for the last 20 years was arrested Tuesday night when he arrived at Kansai International Airport on a flight from Beijing.
Kuniya Akagi, also known by the alias Jun Ogawa, flew to Beijing from Pyongyang in the morning and then flew on to KIA.
It was his first return to Japan since he left in 1986.
Akagi, 52, is the brother-in-law of Shiro Akagi, 59, one of the radical leftists who hijacked a Japan Airlines jetliner in March 1970 and forced it to land in Pyongyang.
Kuniya Akagi traveled to North Korea in 1987 after meeting Shiro Akagi's sister while living in Vienna in the 1980s. The couple moved to North Korea, married and the husband adopted her surname.
Police arrested Akagi on suspicion of violating the passport law by traveling to North Korea despite government restrictions at the time against doing so.
They plan to question Akagi on the disappearances of Keiko Arimoto and two other Japanese from Europe in the 1980s, because he was staying in Vienna around the same time Arimoto was abducted to North Korea.
Akagi told reporters at the Beijing airport in the morning that he does not know anything about the three Japanese.
Akagi and his wife have two daughters who were born in North Korea. The three of them are now in Japan, having left North Korea earlier.