Police on Wednesday launched an investigation into suspected drug use by former professional baseball player Kazuhiro Kiyohara, 48, after arresting him the day before when syringes and what was believed to be an illegal substance were found in his condominium.

The former Seibu Lions and Yomiuri Giants slugger was taken into custody late Tuesday by the Metropolitan Police Department on suspicion of possessing 0.1 gram of an illegal drug at his condominium in Tokyo's Minato Ward while home alone at around 8:45 p.m.

The main ingredient of the drug, which was described as a kakuseizai stimulant, is believed to be either amphetamine or methamphetamine.