A 41-year-old company employee was arrested Friday on suspicion of operating an online dating site that he knew abetted child prostitution, marking the first time a 1999 law prohibiting paid sex with minors has been applied to a site operator, police said.

Kenji Oki, from Toyonaka, Osaka Prefecture, is suspected of operating the site through which a 48-year-old former civil servant from the city of Takaishi in the prefecture was introduced to a 17-year-old female high school student in mid-June, the police said.

Police alleged that through the site, the girl instructed the man to meet her at a hotel in the city of Sakai, also in the prefecture.

The man was fined 400,000 yen after his arrest in September in violation of the same law, the police said, adding that an investigation of the site led them to Oki.

According to police, Oki said he created the site, an online message board accessible on mobile phones, in May to create opportunities for men to hire teenage girls for sex, a practice known as "enjo kosai," or compensated dating.

Seven other underage girls were found to have listed information on the site, they added.