Prokofeva Elena, 28, was found guilty of "procuring prostitution," by a Ho Chi Minh City court. Her ring was uncovered last January after simultaneous raids on hotels in downtown Districts 1 and 3.

The raids found four foreign women, two from Ukraine and two from Russia, having sex with Vietnamese customers. The sex workers said they charged clients VND6 million ($258) per hour, VND10 million for five hours and VND20 million ($862) a day. The deals were brokered by Elena.

Elena was arrested on January 23. She told the police that she had been running the prostitution ring for more than a month.

She said she met young foreign women who needed money through social media networks and got them to come to Vietnam for sex work.

Official data says around 3,000 people are working as sex workers in Saigon, but actual numbers could be higher, experts have said.

Under Vietnam's Penal Code, sex workers are given a warning and cash fines, while pimps and sex ring organizers can get between six months and five years in jail.

Foreign nationals convicted of prostitution also face deportation.