The gang was running two websites bong88.com and sbobet.com, said Major General Trần Ngọc Hà, director of Criminal Police Department. Vietnamnews reported.
Documents recovered during the raid reveal accounts worth up to VNĐ3 trillion ($130 million).
After a large-scale investigation launched by police under the Ministry of Public Security in collaboration with local police, the authorities on Tuesday arrested 11 people, including Nguyễn Hoàng Long, 39, living in District 7, believed to be the kingpin of the gang.
Police also seized more than US$275,000 in cash, electronic devices and thousands of pages of printed documents from football betting accounts.
Long confessed that he and an unknown man set up the online gambling ring in 2017, sharing profits by the ratio of 70 per cent to Long.
Investigations are continuing.