Prosecutors indicted two academics Friday on charges of leaking questions from last year's national dentistry examination in violation of the Dental Practitioners' Law.

Itsuo Ueda, 59, a professor at the Health Sciences University of Hokkaido who served on the national examination board between July 1998 and June 2000, and Kenji Kusunoki, 54, a former professor at Ohu University in Fukushima Prefecture, are accused of leaking questions from the exam to Ohu students. According to investigations, the two conspired with Motoo Niwa, 56, a professor at Nippon Dental University in Tokyo's Chiyoda Ward, also a former national examination board member, to obtain information on the oral hygiene questions prepared for the March 2000 national test.

Kusunoki is charged with including those questions in an exam given in February to final-year students at the university and with passing the information on to students during a lecture.

Prosecutors allege that Kusunoki asked Ueda and Niwa to provide him with the information.

All 25 oral hygiene questions scheduled to be used in the March 15-16 exam were replaced after the then Health and Welfare Ministry received a tip about the possible leakage early in March from a man claiming to be a student of an exam-coaching school.

Investigators plan to further examine whether other people were involved in the leak and to question the trustee head of Ohu University over the school's involvement in the case.

Both Kusunoki and Ueda have admitted the charges. Niwa told investigators that he exchanged the subject matter of national dentistry exams with other exam board members but said he does not remember whether he leaked the information to Ueda.

Niwa, who served on the board until June, was arrested Sunday on suspicion of leaking keywords to questions for the 2000 national exam to Ueda by fax in November 1999. Investigators suspect Ueda then passed on the information to Kusunoki.

The Hokkaido university decided to temporarily suspend Ueda from work following his indictment Friday. Ohu is a private university in Koriyama, Fukushima Prefecture. Kusunoki resigned from the university last September after suspicions arose regarding the leaks.