A 60-year-old principal of a junior high school in the northwest of Tokyo was arrested Thursday on suspicion of soliciting an underage girl for sex last year, local police said.

Hirokazu Tanaka is suspected of violating the country's child prostitution and pornography prohibition laws after promising to pay cash to a then 15-year-old girl at a hotel in Niigata Prefecture last November, knowing she was underage. He denies the allegations, they said.

The two had been in contact via social networking services, while police said it had received information from the girl's guardian in December. The girl was not a student at the principal's school.