The Ho Chi Minh City People’s Court sentenced 23-year-old Kieu Dai Du to prison on Monday after finding him guilty of "procuring prostitution."

Du, who said he did not know soliciting for prostitution was a crime, was pimping for models and beauty queens when he was arrested.

The court however determined that Du's acts were "professional, independent" and helped him earned large sums of money.

It said the sex workers who worked with Du had participated in multiple beauty contests and were famous, which made them difficult to approach. "The defendant had investigated carefully to approach them. What he says [that he did not know soliciting prostitution was a crime] has no basis," said the head judge.

Du had arranged for several women, including a TV host and a beauty pageant contestant, to go to a hotel on Tran Hung Dao Street in District 1 to service four men when he was busted last August.

The TV host and the beauty pageant contestant first agreed to service the men for $600-$5,000, but the price was later increased to $1,500-$7,000 by Du.

Du earned $3,400 from the deal, and he admitted having earned VND19 million ($820) with the same women from previous deals.

The indictment said that Du had participated in several prostitution forums in Saigon as a student. After graduation, he worked as a restaurant manager in District 12 and created a website which published pornographic materials. Du also provided an escort service for businessmen through the website.

Since September 2017, Du had solicited prostitution multiple times online, earning at least VND1 million ($43) for each deal.

Despite prostitution being illegal in Vietnam, sex workers can still be found all over the country's biggest cities. Around 3,000 people are believed to be working as sex workers in Saigon, according to official data.

A debate over legalizing prostitution in the country has remained inconclusive.

Under current rules, sex workers will be given a warning and cash fines, while pimps and sex ring organizers face jail terms.