Opinion | China’s sex industry flourishing despite dangerous conditions and corrupt police

At the White Horse Club, one of Shanghai's grandest entertainment venues, wealthy women go wild each night, partying with tall, muscular men for whose company they pay. It is at least 800 yuan (HK$1,000) for an evening with each Chinese "model", or 1,200 yuan for a foreigner, but the party can go on through the night if the women are willing to fork out a few more thousand.

In Guangxi province 2,000 kilometres away, 20 migrant workers queue quietly along a mud path off a construction site in rural Nanning after sunset. In tall bushes a short distance from them, a young woman "services" a client for 50 yuan every 10 minutes as the others wait in line.

"No one will peep. There's a mutual understanding, like waiting in line for public toilets," says Yang Chun , a Shanghai-based sex coach. Yang is familiar with the sex trade at the grassroots level from her days volunteering in HIV/Aids prevention programmes in Nanning.

"There's no shower in the wild. Each girl will serve dozens of men every night, so most of them would have contracted some form of sexually transmitted disease on their outer vaginal region, even if they use the condoms we hand out."

Because of its large population, China has the most sex workers in the world. But the country's sex industry operates entirely underground, because the Communist Party-led government bans any kind of sex trade. Experts say the ban - coupled with institutionalised corruption and rampant abuse by police with the power to order detention without trial - makes the working environment of those in the trade much tougher.

Professor Pan Suiming , head of Renmin University's Institute of Sexuality and Gender, puts the number of China's sex workers in 2010 at up to two million. The World Health Organisation and a May 2012 report by Human Rights Watch put the number at between four and six million. Other estimates go as high as 20 million, claiming that sex workers contribute as much as 6 per cent of China's gross domestic product.

The nation's underground sex industry comprises a wide variety of workers, from the traditional working girls commonly spotted in salons, saunas and nightclubs to high-end gigolos for women, male prostitutes for gay men, and transgendered sex workers.