Mariko Hayashi, the chairperson of the board of trustees for Nihon University, apologized Tuesday for the “great concern” caused by the recent arrest of a football player on drug charges.

But she defended a series of actions taken by university officials following their discovery of marijuana fragments and pills containing trace amounts of stimulant drugs in early July, denying reports that she was kept in the dark about facts surrounding the case.

Hayashi made the remarks at a news conference held on the university’s campus, following the arrest of 21-year-old student Noriyasu Kitabetake on Saturday. Kitabatake was arrested on suspicion of possessing cannabis and pills with traces of stimulants in his locker in the American football team’s dormitory.