Nguyen Truong Hoat, 25, and seven others, taken in Monday by the Economic Police Department, face charges of “illegal trading in prohibited goods.”

They raided the bar on Co Bac Street in Cau Ong Lanh Ward and found a number of customers using nitrous oxide (N2O), also known as laughing gas.

N2O stimulates the central nervous system, creating euphoria, hallucinations and loss of control over behavior. Its abuse can lead to suffocation, brain damage or even death.

Its use for recreational purposes is banned by law.

The police expanded their investigation and raided a warehouse on Tran Xuan Soan Street in Tan Hung Ward, and found and seized hundreds of cylinders, rubber balloons for filling the gas, specialized filling equipment, and other items.

Investigators have determined that Hoat was the owner of both the bar and the warehouse.

He and his accomplices ran a large-scale illegal operation, buying and distributing the gas across the city since the beginning of this year.

They would fill N2O gas in balloons and provide them to customers at the bar to inhale and also sell to other businesses.

Customers are seen at The Black Lounge bar. Photo by police

At the bar, the check would say “cocktail” for the laughing gas.

Hoat ran a “professional and tight” ship with respect to filling and delivering the gas balloons and recording the sales, the police said.

He even advertised the wholesale and retail sale of laughing gas on social media using a closed network of collaborators, delivery systems and collection of payments.

Members of laughing gas business group run by Nguyen Truong Hoat. Photo by police

Hoat and his accomplices have illicitly earned tens of billions of dong [VND10 billion = US$382,500] in profits this year, they added.

The case is under further investigation.

Two days ago the city police arrested Tran Tuan Kiet, 30, and 30 accomplices for similar crimes.

They were allegedly running an illegal laughing gas supply network that serviced bars and restaurants across the city, earning profits of more than VND105 billion ($4 million) since early this year.