The Tokyo High Court on Thursday upheld a lower court-imposed 14-year prison term for a former Waseda University student who led a group that gang-raped three college students.

Presiding Judge Atsushi Semba rejected an appeal filed by Shinichiro Wada, 30, against the November 2004 ruling handed down by the Tokyo District Court.

"Each of the crimes committed by Wada was heartless, inhuman and extremely vicious, and the damage and impact on the victims are beyond imagination," Semba said.

Wada, organizer of the now-defunct event-planning circle Super Free, and members of the group raped a female university student in December 2001 after getting her drunk. The judge ruled he was the ringleader of the rape, which took place at Wada's home, used as the group's office, in Tokyo's Toshima Ward.

He was also the mastermind behind the gang rapes of two other university students who attended parties sponsored by the group in Tokyo's Roppongi entertainment district, in April and May 2003, the court said.

Thirteen other men involved in the rapes have received prison sentences ranging up to 10 years.