Tokyo police said it suspended a young officer from duty on Monday and referred her to prosecutors for allegedly leaking investigative information to a yakuza she had been dating.
The 23-year-old police officer in charge of detainment at the Shinjuku police station resigned effective the same day as she was charged with a breach of confidentiality in violation of the local public service law.
She was suspected of telling the crime syndicate member in his 30s about the charges against him in an incident between yakuza members, after he asked her in December if he was being investigated, the Metropolitan Police Department said.
The officer has said she gave him the information in the hope of silencing him about their relationship as she thought she would lose her job if it was revealed, according to the police.
The officer was working for a department dealing with organized crime when she contacted him in October from an official mobile phone and started dating the man from late November after being repeatedly asked out, they said.
The officer left the man after he started to ask her for money in January, the police said.
The police also admonished four other officers over the case for failing to supervise her.