Tokyo police arrested Shunichiro Sato, a member of Japan’s national men’s volleyball team, on Thursday on suspicion of cannabis possession in violation of the narcotics control law, investigative sources said.

The Metropolitan Police Department alleges that Sato, 26, possessed dried cannabis at a pachinko pinball parlor in the capital’s Itabashi Ward on Wednesday afternoon.

The MPD found what appeared to be plant fragments from a bag that the suspect had left behind at the pinball parlor, which was later identified as cannabis through forensic testing. The police will conduct a urine test on Sato to determine whether he used cannabis.