Japanese police on Friday arrested a senior finance ministry official involved in coordinating policies with the central bank for possible assault charges, public broadcaster NHK reported.
Heihachiro Ono, 56, deputy vice minister for policy planning and co-ordination at the Ministry of Finance (MOF), was intoxicated at the time of the arrest shortly after midnight, NHK said, citing investigative sources.
He was accused of hitting and kicking another passenger on the subway, it said.
Tokyo police and Japan's top government spokesman, Hirokazu Matsuno, declined to confirm the arrest, reported widely by local media.
The finance ministry cannot immediately confirm the arrest, an official said.
Ono, a career bureaucrat, usually attends the first day of the Bank of Japan (BOJ) board's two-day policy-setting meetings as a finance ministry representative. Government representatives express opinions at the meetings and can delay a vote when they have issues with the board's decision.