The investigation was carried out by Nghe An police in coordination with the Ministry of Public Security's Criminal Police Department and police forces in several provinces and cities.
According to investigators, the suspects organised online gambling through the Sunwin website, offering games such as sic bo, online casino games, card games and football betting.
The network allegedly used encrypted communications and frequently changed bank accounts to evade detection. Gambling proceeds were routed through multiple accounts before being converted into USDT to conceal their origin.
Between May 25 and June 5, police deployed 20 teams across Nghe An, HCM City, Thanh Hoa, Ha Tinh, Vinh Long, Dong Nai, Dong Thap and Gia Lai, arresting 18 suspects on allegations of money laundering and nine others for gambling.
Authorities seized 27 mobile phones, six computer systems and other evidence during the operation.
Investigators identified Nguyen Van Tuan, 38, from HCM City, as the alleged ringleader and administrator of the Sunwin website.
Police said Tuan directed associates to buy USDT and transfer it to wallets under his control. Transactions linked to the operation totalled about VND 75 billion (USD 2.9 million) between May 2025 and May 2026.
The suspects have been charged and placed in pre-trial detention while investigations continue.
