Police in the Mekong Delta province of Bac Lieu Friday busted an illegal lottery gambling racket that took bets of up to US$5,000.
Tran Thi Lien, the alleged 44-year-old ring leader of the game called so de, has been arrested.
The case is considered the biggest ever found in the province.
So de is an illegal numbers game based on the state lottery, allowing players to bet any amount they want for payoffs up to 80 times the original wager.
The police seized a lot of the game exhibits from Lien's house, including VND350 million in cash, calculators, fax machines and a hard drive for cameras to track strangers coming into the house.
A police officer said that the game involved a large number of gamblers, who put millions of dongs to around VND100 million on each original wager.
Many people were seen walking around Lien's house and making phone calls as the house was being searched by the police.
The woman has a previous conviction on so de gambling.
Bac Lieu police have awarded the officers participating in the case VND20 million.
Police have launched further investigations.