Macau police have arrested 15 residents over alleged links to an online gambling ring believe to have brought in some $3.69 billion in bets since 2017.

According to a police briefing, the arrests were carried out in conjunction with mainland Chinese authorities in the Guangdong province, with a further 27 people arrested for alleged involvement in the gambling operation.

According to reports, the alleged criminal organization was based in Macau, with various other bases in mainland China, however, the majority of their operations and internet servers were based outside of China.

In total, some 42 people have been detained, including the alleged ringleader of the group – a 36-year-old Macau local, being accused with numerous crimes including money laundering.

The Macau operations were operated out of Macau’s NAPE business district, with accounts being collected in a mainland Chinese bank account.

During the raid, Macau police collected over HK$10 million in cash, also seizing mobile phones, laptops and routers.

Police originally got wind of the operation in March of 2021, finding out that operators were based in Macau, mainland China and Taiwan.

The illegal online casino allegedly supported games such as online baccarat – the most popular game for Chinese punters – as well as football betting and other types of games.

Wagers were settled in numerous forms, including cryptocurrency, with the group allegedly making up to $3.71 million in profit over the years of its operation.