Beijing police have broken up an illegal World Cup betting syndicate worth 320 million yuan (US$48 million) and apprehended 46 suspects, state media reported on Saturday.
Police in the Chinese capital said 200 officers had been involved in the crackdown, which formed part of the nationwide Operation Chain Break targeting sports betting.
Gambling is strictly prohibited in mainland China apart from the government-run sports lottery.
Fourteen of the suspects have been placed in criminal detention and 21 in administrative custody. The other suspects, who were held on Friday, were still under investigation.
Police believe that six masterminds had been operating as middlemen for foreign gambling websites to recruit agents and customers.
The ring is thought to have used popular messaging sites such as WeChat to advertise the odds available for each day’s matches.
The value of the transactions linked to the ring had reached 320 million yuan, according to police.
China has the world’s largest population of soccer fans, although its national team has only appeared in the World Cup once.
The tournament, which concludes next Sunday, has seen tens of thousands of Chinese fans travelling to Russia to watch games.
Foreign gambling sites have been known to target Chinese fans in the past and are thought to have been trying to cash in on the World Cup.
Chinese language adverts for gambling sites often appear online and sometimes during live broadcasts of European soccer matches.
There have been a string of arrests linked to online betting since the start of the World Cup. Last week police in the southern city of Shenzhen arrested nine people, while another 11 were detained in the eastern province of Zhejiang.
In recent posting on social media, Beijing police warned fans of the dangers of trying to overseas gambling sites, claiming 95 per cent of them were actually phishing sites.
They also reminded people that it is illegal to bet online and the authorities would continue pushing to eradicate gambling.