"A completely US story, some Chinese money, a few Chinese faces and some Chinese elements - these kinds of films are not real co-productions," Zhang Pimin, then deputy chief of the State Administration of Press, Publication, Radio, Film and Television, said in 2012.

The SAPPRFT reiterates that in an officially acknowledged co-production, at least one-third of the leading cast should be Chinese, the story should have Chinese elements and there should be Chinese investors.

"Film in China is not merely a cultural product," says director Wang Fan, who is co-producing a film with Canadian filmmakers. "What our authorities really want from co-productions are films with a strong Chinese point of view that help to promote China's soft power in the global scene."

But to make such a film and expect a profound international influence is very demanding, even for Alfonso Cuaron, director of the sci-fi epic Gravity, which grossed $716 million around the world and won seven Academy Awards.

"You cannot calculate co-productions in terms of the content," the Mexican director told the panel. "Every Chinese element needs to be organic in the film, because the Chinese audience will enjoy the film for what it is, not because it has some Chinese elements."

The Chinese elements in Gravity, such as the Chinese space station Tiangong and space ship Shenzhou, were not deliberate, he adds, because when he planned the film five and half years ago, they were what was in space, way before co-production became a focus.

He says co-productions should be motivated by cultural curiosity, not financial transactions.

"For me, a film about people in the cultural context of China is very intriguing," he says. "I would feel more intrigued by doing something here in Chinese, a Chinese story, and bringing my ideas to the story."

French director Jean-Jacques Annaud is currently in the middle of filming Wolf Totem, based on Chinese writer Jiang Rong's best-seller about the experiences of two young men in the Inner Mongolian grasslands. The film will be released at Christmas, according to producer Wang Weimin.