Seven people have been arrested for operating an illegal gambling site, marking the first instance of an online casino operator being arrested on suspicion of gambling racketeering in Japan, Kyoto Prefectural Police have said.

The suspects comprise men and women in their 20s to 40s, including U.S. national Randall Aaron Asher, a 36-year-old company employee residing in the city of Urayasu, Chiba Prefecture.

The suspects, arrested Sunday, are accused of working for the foreign company operating Dora Mahjong, a membership-based gambling site catering to a Japanese audience, facilitating games and collecting commissions.

Authorities estimate that approximately ¥2.3 billion ($15.3 million) in deposits were made since the site’s launch in 2011. Despite the suspects asserting the site’s legality, online gambling is illegal in Japan.

The cyber investigation division of the prefectural police confirmed the case through cyber patrols. Investigative sources revealed that the suspects collected 10% to 15% of customers’ gains as commissions. The site had more than 70,000 registered members.

The suspects were arrested on an initial charge of allowing six Japanese customers to gamble on mahjong on the site between March and December last year and collecting commissions.

While three suspects, including Asher, admitted involvement, the remaining four contested some allegations, claiming that although they were involved in running the site, they did not think the work they were tasked with was illegal, NHK reported.

Investigators are now examining potential charges against the site’s users.

Regulating online gambling can be tricky, particularly when site operators are based overseas in countries where it is legal.

According to data from the National Police Agency, 307 individuals were arrested for offenses relating to online gambling between 2020 and 2022.

The agency has emphasized the legal risks associated with online gambling and urges the public to exercise caution.

Information from Kyodo and Jiji added