Police in Tokyo have arrested a 21-year-old member of Nihon University's American football team for allegedly possessing marijuana and a stimulant drug at his dormitory.

The suspect is a third-year student, Kitabatake Noriyasu.

The arrest on Saturday comes after the staff of the university discovered a plant fragment and a tablet in the team's dormitory following a tipoff in early July that a member had been using marijuana there.

A police examination confirmed that the fragment was from a marijuana plant and the tablet contained stimulants.

Police conducted a search at the dormitory on Thursday while searching for their owner.

Police made the arrest, citing the discovery of the fragment and the pill in a box attached to the suspect's bed.

They are investigating whether the suspect used them and how he obtained them. They are also looking into whether other team members were involved.

Police have not clarified whether the suspect has admitted to the charges.