Police initially detained six people involved in the ring on July 3, including Tran Quoc Khoi, 66, Phan Thanh Tam, 53, Dip Mot Sang, 52, Nguyen Thi Thu, 37, Huynh Cao Hoach, 30, and Nguyen Thuy Trang, 28.
On searching their houses in Ho Chi Minh City, police seized 11 ATM cards, $1,100 in cash, 4 taels (4.8 ounces) of gold, seven mobile phones, equipment and devices, and a lot of materials related to football betting.
Of the detainees, Tam and Hoach were big football bettors while the other four were the ring operators, police said, adding that they are continuing to track down others.
Football betting is banned in every form in Vietnam.
The ring operated through the website M88 with a server located aboard, police said, adding that it was run on a very large scale through close coordination between foreigners and Vietnamese people.
Preliminary calculations showed that the total betting amount via the ring was more than VND1.4 trillion ($65.8 million).
In order to bet via the M88 website, bettors are required to pay a deposit to an overseas bank account, and the deposited money will be converted into a number of points for use in betting, investigators said.
Major General Ho Sy Tien, a police chief, said that investigators have found out important clues that will help identify every bettor and their betting amounts.
“Therefore, we call on those who have been involved in the ring to present themselves to police soon to be given clemency,” the official said.
Last year, police also arrested a dozen bettors and organizers of illegal football betting through the same website, with wagers reaching hundreds of billions of dong (VND1 billion = $47,000).