Zhang Yu

When the aspiring actress Zhang Yu decided she wanted to blow the whistle on some of China's top TV and film-makers - those who have demanded sex in return for roles in their soap operas and movies - she chose the internet to make her case.

Zhang says she won all her roles through sleeping with the directors, assistant directors or men in charge of casting. She also made films herself - of the casting couch sessions. Then she rocked the film and TV world by releasing 20 graphic sex videos of her and a host of big names.

The videos are an insight into how China's casting couch works and millions of Chinese have logged on to the websites, prompting a debate over what is justifiable content on the Web.

"Why should a woman suffer in silence and bear with all the unfair treatment?" Zhang asks in her blog. "If you have to mix with beasts and snakes and you are not venomous, how shall you survive?"

She has little legal ground for complaint, as all of the videos show scenes between consenting adults, but her actions are still causing a huge stir in China.

Some internet users are shocked that household names would abuse their positions so shamefully, while others have merely had their worst fears confirmed about how things work in the film business. Shocked or saddened, in their hundreds of millions they are logging on to the websites showing the clips.

It has certainly helped to boost the profile of the actress, and the top Chinese website Sina.com has a section devoted to Zhang, who had few major roles to her name before she started her campaign against the casting couch.

Zhang, 30, comes from a poor farming community in Hubei province, and insists the reason she is exposing the Chinese casting couch is because she wants to uncover what is referred to as the industry's "hidden rule", and thus challenge the powers-that-be who exploit young women.

She had complained for years that certain directors and producers demanded sexual favours from unknown young actresses in exchange for plum roles, but no one was listening.

She started making the accusations in 2002, saying that a director had asked her to arrange sex for him with another actress in exchange for a movie role. The director's defence was that he was drunk and couldn't remember the incident. It blew over.