Japanese police have arrested five men including an executive of a group referring women it found on social media to sex trade shops across the country, sources said Tuesday.

The group executive, Kazuma Endo, 33, is denying violating the employment security law in the case, while the other four have admitted to it, according to sources at the joint investigation headquarters of Tokyo's Metropolitan Police Department and the Oita prefectural police.

According to the sources, the group, called "Akusesu," had about 160 members who used aliases among themselves. Police are investigating the group as a tokuryu anonymous, fluid criminal network.

The group is believed to have earned hundreds of millions of yen in referral fees by sending women to a total of about 350 sex trade shops in all prefectures except Shimane in western Japan.

The group allegedly lured women by advertising high-paying jobs on X, and made them send personal information such as face photos and identification documents.

The group then showed the data to sex trade shops and sent women to stores where the pay and other aspects of the job matched their conditions. It received 15% of the women's pay as referral fees.

The arrest warrant for Endo cited suspicion that he introduced a woman in her 20s to a sex trade shop in the Oita city of Beppu around February. The suspicion surfaced when police raided the shop in June in a separate case.