On November 23, Hanoi authorities announced the indictment of several individuals involved in the scheme:

Nguyen Tuan Linh (born 1987), Pham Minh Giang (1986), and Dang Huy Hien (1983), all Hanoi residents, face charges of smuggling and violations of accounting regulations causing serious consequences.

Chu Bich Ngoc (1986, Hanoi) and Nguyen Thi Hien (1976, Hai Phong) are charged with accounting violations.

Hoang Bui Khanh (1985, Hanoi) faces smuggling charges.

The investigation began after Hanoi police discovered suspicious activities by Nguyen Tuan Linh and his associates involving N2O imports through DCMC Vietnam Trading Company.

On November 7, police summoned 26 individuals and conducted emergency searches at eight locations, seizing:

129.3 tons of N2O
Various tools and equipment
23.17 billion VND in cash
$9,300 in foreign currency

Linh collaborated with Giang, Hien, and Ngoc to establish DCMC and Tam Moc companies. They operated a filling plant in Tan Tien, Hung Yen province, to import N2O for distribution. The gas was primarily sold to bars, pubs, and clubs.

The DCMC company saw frequent leadership changes:

Khanh served as director from 2019 to November 2022.
Hien assumed the role from December 2022 to March 2024.
Giang has been the director since March 2024.

Since 2019, DCMC filed 364 import declarations for N2O, declaring it as a food additive with a total volume of 7,338 tons worth approximately 126.8 billion VND. The gas was transported to warehouses in Hung Yen and Bac Ninh provinces.

Most of the imported gas was sold to Royal Gas Company (later renamed Song Bien Clean Food Company), operated by Nguyen Luong Ha, who is currently serving a sentence at Xuan Nguyen Prison and is internationally wanted by Czech authorities for producing narcotics.

From 2022 onward, DCMC declared the importation of 6,190 tons of N2O worth 108.3 billion VND, ostensibly for food production. However, only a small portion was used for this purpose, with 4,327 tons sold for other uses.

Royal Gas and Tan Loc companies paid DCMC approximately 260 billion VND, but DCMC only declared tax on 115.13 billion VND, evading taxes on the remaining amount. Authorities estimate tax losses for 2022-2023 alone at 23.73 billion VND.

Tien Dung