Medical school director Tetsuo Yukioka apologized Tuesday for "betraying public trust," saying women should "not be treated differently because of their gender."

Last week, Japanese media reported that the university had manipulated the scores of female applicants to keep the ratio of women-to-men at 30 percent.

Kyodo news reported Tuesday that female scores had been docked as early as 2006.

University vice president Keisuka Miyazawa said such alterations "should never happen" and pledged that next year's exams would be fair.

Other medical schools to be vetted

Education Minister Yoshimasa Hayashi said he planned to vet entrance procedures of all medical schools amid expert claims that such discrimination was widespread.

Hayashi plans widespread vetting of medical schools

The scandal had emerged as investigators looked into claims that the son of an education ministry bureaucrat was elevated on points to just above entry level - despite failing the exam three times.

Investigators said the school had wanted fewer female medical graduates, arguing potential motherhood would shorten or halt their careers.

"Women often quit after graduating and becoming a doctor, when they get married and have a child," one source told the Yomiuri Shimbun newspaper last week.

Practice "extremely disturbing'

Women's empowerment minister Seiko Noda told Japan's NHK public broadcaster the exam points manipulation had been "extremely disturbing."

Investigators found that in this year's entrance exams the school reduced all applicants' first-stage test scores by 20 percent and then added at least 20 points for male applicants, except those who had failed four times.

Nearly 50 percent of Japanese women are college educated – one of the world's highest levels – but often face discrimination.

Outside care services are limited. Men are expected to work long hours while women are lumbered with homemaking, child-rearing and care of the elderly.

ipj/rc (AP, AFP)