Former professional baseball player Kazuhiro Kiyohara, who was arrested last week for alleged drug possession, frequently changed the locations of his rendezvous with his supplier to avoid being detected, investigative sources said.
The former slugger has admitted using an illegal stimulant, and the sources say he probably started taking it last summer.
Kiyohara has refused to reveal his supplier and the police believe there is a yakuza connection.
According to the sources, his meetings with the seller were mostly in Gunma and Tochigi prefectures. In one typical pattern, Kiyohara would first head to a hotel in those areas and return to a hotel in Tokyo.
Before his arrest Tuesday, Kiyohara visited Gunma and stayed at a Tokyo hotel Monday upon his return, the sources said. Police have determined his supplier separately headed for Gunma on Monday, the sources said.
The former baseball star was arrested late Tuesday when syringes and what is believed to be an illegal substance were found in his condominium. He was taken into custody on suspicion of possessing 0.1 gram of a stimulant and has already admitted it belonged to him, and that he used it himself. Urine samples confirm he used the substance.