The Metropolitan Police Department on Wednesday arrested an official of the Social Insurance Agency and two dentists, including a former executive of the Japan Dental Association, on suspicion of bribery in connection with the agency's supervision of hospitals.

Investigators arrested agency official Harumi Sato, 57, former dental group executive Fumihiro Uchiyama, 66, and dentist Yoshimi Otomo, 73, on suspicion that Sato took more than 2 million yen in cash in bribes from the dentists.

Sato told police he received money and the other two admitted to the allegations, investigators said.

The police suspect the three, all Tokyo residents, developed cozy ties because they are all alumni of Tokyo Dental College, they said.

Sato was in charge of supervising hospitals to make sure their claims for medical service fees from medical insurance systems were proper.

Police suspect the agency official received the money while working at the Tokyo regional social insurance office from 2002 to 2005 in return for not properly supervising the claims for hospital fees, they said.