Koichi Nakamura, vocalist for the Japanese pop group Jaywalk, was arrested Tuesday on suspicion of stimulant possession, police said.

Police found a small amount of amphetamine in a car parked in Tokyo's Minato Ward at around 2:20 a.m., while questioning the 59-year-old musician, who was inside the vehicle, they said.

Nakamura initially claimed the substance was medication prescribed by a dentist, but later admitted it was amphetamine, police said.

Jaywalk, formed in 1980, is famous for its hit "Nanimo Ienakute . . . Natsu" ("I can't say anything . . . Summer").

Recently, the country's show business industry has been rocked by a string of drug busts, including the arrest of pop idol-turned-actress Noriko Sakai last year, who got a suspended prison term last year.