A member of the Saitama prefectural board of education served as a supervising editor of a history textbook, an education ministry document revealed Tuesday, making it a conflict of interest for him to be involved in the board's textbook selection.

The Education, Culture, Sports, Science and Technology Ministry prohibits authors and editors of textbooks from being involved in their selection.

Shiro Takahashi's position on the Saitama board could be problematic as he is in a position to influence textbook selection.

Takahashi, a professor at Meisei University in suburban Tokyo, is a former deputy chairman of the Japanese Society for History Textbook Reform, which criticizes mainstream Japanese history textbooks as being "biased against Japan" and marked by "self-denigration."

The revised edition of the junior high school textbook, authored by the society and published by Fusosha Publishing Inc., was approved by the education ministry earlier this year.

Critics say the textbook glosses over Japan's wartime atrocities and its approval was one of the reasons behind massive anti-Japan demonstrations in Chinese cities in recent weeks.

It is up to each prefectural board of education to decide if it is appropriate to allow editors and authors to be involved in discussions about textbook selection. Takahashi said he would leave the room when the board makes a decision.

He was appointed a member of the Saitama prefectural board of education in December.

This year, the ministry began disclosing the names of all those involved in creating textbooks to ensure fairness in the school boards' selection processes.

The society textbook had included Takahashi as a supervising editor when it applied for ministry approval in April, but it was deleted at his request just before his appointment to the Saitama board.

The ministry has listed Takahashi as a supervising editor of the textbook.