Hundreds of police officers from very 30 units launched raids early this week and summoned many people for questioning from Hanoi, Ho Chi Minh City, and the provinces of Phu Yen, Dong Nai, Long An, Bac Lieu and Ca Mau.

The Ministry of Public Security said 22 individuals have been arrested for gambling and organizing gambling, including a foreigner suspected to be in charge of managing and operating the ring.

According to the police, the ring's gambling website xxx88.com attracted hundreds of thousands of players across many provinces and municipalities, with transactions worth over VND30 trillion ($1.3 billion) carried out through 4,000 plus agencies.

The ring's gamblers mainly paid through online banking and other fast money transfer methods, and many were found to hire other people to open bank accounts for them so they could hide their participation in football betting.

The gambling website's server is located overseas, police said.

Vietnamee authorities have relaxed their stance on gambling as a "social evil," legalizing sports betting in 2017, and allowing Vietnamese citizens aged over 21 with a monthly income of at least VND10 million ($445) to play in a casino resort in Phu Quoc Island on a pilot basis. 

Online betting, however, remains illegal.