Tokyo police have arrested four men on suspicion of brokering prostitution abroad through a website, people familiar with the investigation said Thursday.

The four men were arrested for alleged violation of the employment security law, the first arrest in Japan in a case involving providing recruitment information on harmful work, according to the Metropolitan Police Department.

The police said that the four men, including Ryosuke Imamura, a 37-year-old operator of the website, are suspected of introducing two Japanese women in their 20s to 30s to brothels in New York and Washington, respectively. The women had applied to prostitution job listings on the website.

The website was launched around June 2021. The men sent between 200 and 300 Japanese women to brothels in the United States, Canada and Australia over three years, logging revenues of roughly ¥200 million, according to police.

The Tokyo police said that the four men's involvement in the case came to light after U.S. investigative authorities in April last year provided them with information about Japanese women suspected of traveling for prostitution and about the website.

There have been several cases in which U.S. authorities denied entry to Japanese women suspected of traveling for prostitution, the police said.