No one knows how many thousands of women on the mainland have been abducted, raped, beaten, enslaved and sometimes literally chained to their stoves. In a money-dominated society, young women are often traded like stolen treasure. Baby girls are abandoned with less care than an unwanted pet.
All this is reflected in Li Yang's new film, Blind Mountain (Mang Shan), but Li says he's exposing something even worse. His second feature tells the story of Bai Xuemei, a woman in her early 20s who is tricked into going to the countryside for work, but sold as a bride to a farmer in a remote village. Li has a Hitchcock-like cameo at the start of the film, playing the human trafficker who sells Bai to the 40-plus Huang Degui and his parents.
Bai's mood shifts between defiance and resignation. We see her transform into a mother and farmer's wife, and her desperate attempts to escape over the mountains from the desolate village. After 95 minutes, the grim ending comes suddenly and unexpectedly.
Beijing-based Li says he sought to make a 'relentless, non-judgmental exposure of all kinds of human ugliness, greed, brutality and trickery'. He says his film is 'a call for the return of humanity, the return of love and the ability to tell right from wrong'.
Li's first feature film, Blind Shaft (Mang Jing), told an equally bleak story of migrant workers in the coal industry. It won a Silver Bear at Berlin in 2003.
In Blind Mountain, Li and cinematographer Lin Liangzhong again employ a documentary style in their filmmaking. Lin is best known for his work with Taiwanese director Ang Lee in the 1990s.
The blindness referred to in both of Li's film titles is what he sees as ignorance of a moral decency that has been eroded by the rapid economic and social development of modern China. Blind Mountain is set in northern China in the early 1990s. 'Trafficking of women still exists, but it was more common in the early 1990s,' Li says.
The traditional preference for boys to farm the land and care for parents later in life is a major reason behind the trafficking of young women, some of whom are sold for marriage by their own poor families.
The one-child policy introduced in the late 70s has encouraged gender-selective abortions and even female infanticide, raising the ratio of male to female births to 120:100 in some parts of the mainland. In Blind Mountain, this message is brought home by a scene in which villagers try to reel in a baby girl found floating face down in the middle of a pond.
Li wrote the script after travelling to the southwestern province of Sichuan to interview women rescued from ordeals similar to Bai Xuemei's. In a small indication of the scale of the problem, state media said police in the neighbouring province of Yunnan rescued 4,000 abducted women from 2000 to 2004.
Most of the women Li met in Sichuan were also rescued by police. 'The chances of running away themselves are slim, because in these villages there are always people watching the women, keeping them under surveillance and making sure there's no escape.'
Li used just two professional actors in his film, scouring local villages to find people to play other parts. Beijing Film University student Huang Lu plays Bai. Yang You'an, who plays Bai's husband-owner, normally works as a decorator. The locals who played Huang's parents have both worked as village officials.
The novices convincingly recreate lives that are all too familiar to them. When presented with the script, the actors thought the story was 'totally normal', the filmmaker says.
The state film bureau also saw his depiction of abduction, rape and domestic violence as normal when it approved the script. But officials asked for changes to the completed film, and Li says he tried to go through the approval process before its debut at Cannes.
Several Chinese films tipped to make the 60th Cannes lineup were absent, making Li's work this year's highest-profile film shot on the mainland. Li, who lived in Germany for 14 years, says this doesn't make him a standard-bearer for mainland filmmakers at the festival.
'I can't say I represent them, but I'm still a Chinese director,' he says during post-production work in Beijing. 'The films I shoot are about China, and I understand the real situation at the lowest level of society.'
Not surprisingly, state media virtually ignored the unapproved film after Cannes announced its inclusion. A brief report on the Sina.com website says Li was interested in promoting the same 'harmonious society' that has become the latest buzzword of the government. Li says there's some truth in the report.
'You can say that, because I pay attention to humanity,' he says. 'Of course, I hope society can be quite harmonious, but you have to resolve the contradictions.
'What Chinese society most lacks now is a kind of love, a care for humanity. If the people in this story had shown a little caring, a little more help, it would be impossible for this young woman to be sold into this situation.
'There are officials everywhere, there are police everywhere,' he says. 'But they don't help her.'
Despite the gritty realism, Blind Mountain contains moments of black humour. A family-planning slogan painted on a farmhouse wall promotes the one-child policy: 'The path to wealth: First plant trees; bear fewer children; raise more pigs.'
Li is reluctant to reveal the low budget of his film, which, like Blind Shaft, was paid for out of his own pocket with some private funding.
The 48-year-old, a former actor with the China Youth Arts Theatre, was born in Xian to a family of thespians. He studied film directing in Beijing and Germany, where he worked as a TV camera operator. After starting his career with documentaries, Li was attracted to the realistic story line he adapted for Blind Shaft from Liu Qingbang's short story Sacred Wood (Shen Mu). Through his characters in both Blind Mountain and Blind Shaft, Li aims to criticise the passivity of people in the face of moral degeneration. 'Money has become their standard measure for judging things,' Li says.
The upheaval brought by decades of economic and social change means 'China's traditional morality and value concepts have faced enormous challenges and are close to collapse'. Such a meltdown of virtues is reflected in the way the village holds Bai prisoner.
'They know what's bad, but they keep silent,' Li says. 'This is what I want to criticise. The things that they all believe are normal bring tragedy to other people. This can happen in any society. Perhaps it's even more terrible that everyone turns a blind eye to these things.'
The 60th Cannes Film Festival begins on Wednesday