BEIJING — Documentary maker Zhao Liang’s harrowing take on the lives of those cast aside by China’s economic miracle caused a stir in Cannes this year and brought attention to bear on a remarkable new talent from China.

“Petition — The court of the complainants” documents the plight of China’s judicial “petitioners” — people from across the country who come to the capital Beijing in the hope of righting legal wrongs suffered back home. The idea of petitioning is an ancient one, dating back to the times when emperors ruled China.

A stylish and direct piece of work, “Petition” is critical enough that it will likely never get a major Chinese release, although the fact these kind of films are being made at all shows that China is changing.

Zhao is driven by a need to document the remarkable transformation of Chinese society that has taken place in the last 30 years of reform.

“In the late 1990s, China’s urban transformation and economic reform were like a rising wind and scudding clouds. Every person living in China’s big cities had strong feelings about it,” says Zhao.

While China is on a path to greater openness, challenges remain.

The heroes of Zhao’s documentary include peasants from the countryside whose farms have been confiscated to make way for real estate scams and workers from closed-down factories. He has followed them for over a decade, since 1996, in the alleys and huts of “Petitioners City” near Beijing’s South railway station.

“I had just graduated from Film Academy at the time, and was looking for creative routes, and documenting this kind of social change seemed a very strong mode of expression. Everyday was like stealing things from a fire.

Zhao currently has no plans to move into narrative films.

While “Petition” is unlikely to be shown on major release in China, the fact Zhao is a documentary maker means that the 38-year-old escapes some of China’s stricter policies — he did not need to request an official permit in order to film nor did he require official authorization to show his work at Cannes, where it was out of competition.

Over the years, Zhao has won several prizes for his documentaries, and he won Best Documentary at France’s Festival des Trois Continents for “Crime and Punishment,” a film detailing daily life in a police station.

The Chinese film industry is booming, but Zhao describes the biz as “abnormal,” saying the result is that “it becomes a tool of the ruling class tool to fool the public.”

“When I started shooting my films, they were for the Chinese people to watch, or even future generations. Only in this way my films can have the greatest significance. My hope that every Chinese person can watch my movies. It is a pity that it is still difficult,” he says.

The greatest challenge of lensing in China, Zhao says, continues to be working in an independent spirit.