Japanese experts were divided over why a man claiming to be Kim Jong Nam, the eldest son of Pyongyang leader Kim Jong Il, tried to enter Japan under an alias with a forged passport.
The man was deported to China on Friday after being detained by immigration authorities since his arrival Tuesday at Narita airport in Chiba Prefecture.
Yasuhiko Yoshida, a professor at the Osaka University of Economics and Law, said that if the man turned out to be Kim Jong Nam, he simply "wanted to come to Japan covertly" for personal reasons.