Last month's arrest of a Tokyo man over an organ trading scam came as a shock not just because he was a doctor attempting to get a kidney for himself, but also because he was collaborating with the yakuza to fake an adoption to obtain the organ.

Toshinobu Horiuchi, 55, was arrested after allegedly paying ¥10 million between 2009 and 2010 to gangster Kazuhisa Takino, 50, who Tokyo police say acted as a broker in the bogus adoption.

The gangster, Horiuchi's wife and two other people were also arrested for their alleged involvement in the case.