Tokyo police on Monday arrested two members of Natural, one of Japan's biggest sex worker scout groups, for allegedly introducing women to sexual service establishments.

The Metropolitan Police Department arrested Yuya Ogino, 32, and Ryosuke Itani, 27, on suspicion of violating the employment security law through harmful job introduction.

According to the department's division dealing with yakuza crime syndicates, Natural began its activities mainly in Tokyo's Kabukicho nightlife district around 2009.

The group had up to about 1,500 scouts nationwide, and its annual revenue is believed to have reached about ¥5 billion. The division suspects that some of the money may have gone to such syndicates.

On Monday, the Tokyo police searched dozens of locations related to Natural, including sexual service establishments, in Tokyo and some other prefectures.

The arrested two are suspected of introducing women in their 30s to such establishments in Tokyo and the city of Toyama between around July 2023 and March 2024.

Investigative sources said Natural members illegally introduced women they found on the street to thousands of establishments across the country, including sexual service businesses and hostess bars, and received fees from the establishments.

During the current parliamentary session, the National Police Agency is expected to submit a bill to revise the law governing adult and other entertainment businesses to regulate such fees.