Guangdong province police have broken up an illegal World Cup betting ring, involving more than 10bn yuan ($1.5bn) of cryptocurrency bets.
The gambling platform was run on the dark web, a service which is not indexed on traditional search engines, making it much harder for law enforcement to track down.
Guangdong police said Bitcoin, Ethereum and Litecoin were the only currencies accepted on the platform.
Six suspects were arrested, and a total of 5m yuan in bank accounts has been frozen, with over $1.5m in cryptocurrencies seized.
During its eight-month run, the site attracted 330,000 registered users from multiple countries, and was said to have 8000 agents in place to draw in new users, in a pyramid-style scheme.
The gambling syndicate “used the loophole that virtual currency is not effectively regulated in our country” to make huge profits, police said.
This is part of a crackdown on illegal sports wagering since the start of the World Cup, which has also seen Chinese authorities close down an operation in Beijing.
Using the WeChat software, the operation netted approximately 320m yuan during the World Cup.
This also coincides with the closing down of 50000 WeChat accounts and over 8000 groups related to illegal activities.
Chinese laws restrict people to one form of sports wagering on the mainland, the China Sports Lottery, which has been a dependable market, drawing in $16.5bn in sales in the first quarter of 2018.