She has nothing to gain, insists Ms Ye Haiyan, who describes herself as an advocate for sex workers in China.

"I just want to speak up against the heavy-handed, moralistic approach that the authorities here have towards the sex industry," she says.

She admits that she expected the controversy when she decided on her stint early this year.

"That's why I decided to be open about my experience and share it (on her Weibo microblogs)," says Ms Ye.

Weibo is China's answer to Twitter.

"I knew the outreach of the Internet and how powerful it is."

True enough, her story went viral. It also cast the spotlight on the plight of sex workers in China.

But the reactions were mixed.

She says: "The (letters of) encouragement and support poured in, many of which declared that I was brave, that I wasn't just all talk and no action.

"Then there was the other group of people who felt that I'd debased myself. They slammed me for being immoral and shameless."

Ms Ye, who founded the China Grassroots Women's Right Centre in 2006, says she was appalled to find out that many of the sex workers refused to use condoms.

"We wanted to promote safe sex and HIV-preventive measures, but these women were afraid of being caught with the evidence (the condoms)," she says.

According to the China Daily Asia Pacific in June, prostitution is illegal in China "but the World Health Organisation estimates that there are some four million sex workers in the country".

Some experts suggest that the real figure may be higher.

Ms Ye says many of these women who have to resort to prostitution often don't have a choice.

"Unless you are in their shoes, you can never understand how much courage it takes."

All too aware of the cynical views, she says: "It's easy to condemn the prostitutes.

"But for those who (sell their bodies) in the rural areas, the sanitary conditions are so deplorable that you don't even want to set foot inside a room.

"Then there are the occasional clients who can turn violent or abusive. No one can really tell from first impressions until it happens. Then it's too late.

"Adding to the prostitutes' woes is the fear that the police will come knocking on their doors."

Prostitutes face fines of up to 3,000 yuan (S$600) if they are caught. Ms Ye points out: "Do your math and you'd know that for someone working, say in the Ten Yuan Brothel and who has to pay $15 a day for rental (of the room), you know how crazy that is."

Her motive is simple: Legalise the trade, drop the monetary penalty.

But she recognises that she has a "near-impossible mission". She says, with a sneer in her voice: "The authorities don't take too kindly to people like me, so they continue to invite me for a visit to the police station. For now, it's good enough to keep raising awareness of these women's predicament."