The son of prizewinning writer Masako Togawa was arrested early Monday in Tokyo for possession of stimulants and marijuana, police said.
Shosaku Togawa, 25, a restaurant worker, had 0.7 gram of stimulants and 3 grams of marijuana hidden in his car when he was taken into custody in Shibuya Ward at around 5:30 a.m., police said.
Togawa said he suffers insomnia and started using drugs about a year ago, police alleged.
He reportedly told police he obtained the drugs in the Shibuya entertainment district.
His mother, whose real name is Masako Uchida, 72, received the Edogawa Ranpo Award for her 1962 debut mystery novel, "Oinaru Genei" ("Grand Illusion").