Japan's education ministry on Friday began a probe into entrance exams at university medical departments after Tokyo Medical University admitted to unfairly lowering the scores of women applicants to curb their enrollment.

The ministry also announced it will set up a team of experts to look into its employees' compliance with rules in the wake of arrests of senior officials in graft scandals linked to the same university.

The rigging of scores at Tokyo Medical University was "extremely inappropriate and a serious matter that eroded trust in universities," education minister Yoshimasa Hayashi said at a press conference.

Noting that other universities may have engaged in similar misconduct, Hayashi said, "I want each university to sincerely answer the ministry survey."

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In questionnaires sent to 81 universities, the ministry asks the schools to report the pass rates for entrance exams over the last six years. Responses to the survey must be submitted by Aug. 24, with the final results expected to be released in September at the earliest.

(A protester holds up a sign saying "Just because we are women")

The schools must provide explanations if there are significant disparities in pass rates between men and women or different age groups.

If the explanations are deemed unsatisfactory, the Ministry of Education, Culture, Sports, Science and Technology may ask additional questions or conduct on-site inspections.

The ministry will also demand that schools clarify criteria for marking and disclosing scores to unsuccessful applicants. It will also check whether admission decisions are made without knowledge of candidates' names and gender.

An internal probe panel of Tokyo Medical University said Tuesday the school had unfairly inflated the scores of certain students while deducting points from women applicants and candidates who had failed the school's exam more than three times to keep them out of the university.

Sources have said the university set a ceiling for women's admission of about 30 percent and did so to avert a future shortage of physicians as a result of women doctors resigning or taking long periods of leave after marrying or giving birth.

The rigging of scores came to light after Futoshi Sano, former director general of the ministry's science policy bureau, was indicted for bribery after securing the enrollment of his son in the school in return for helping the university to be selected for a ministry funding program.

Another senior bureaucrat, Kazuaki Kawabata, former director general for international affairs at the education ministry, was arrested for bribery after being wined and dined by a consulting firm executive in exchange for providing favors to the company.