“Slumdog Millionaire” helmer Danny Boyle has bemoaned China’s censorship rules as “regrettable” but said he would still be keen to make a movie in China.

“I know there are restrictions on filmmakers, which from our perspective are regrettable,” Boyle told a panel at a meeting of the Shanghai Film Festival, where he is chairing the competition jury. “Great artists who work here — and there clearly are great artists — should be free. It’s very important and valuable to the society that they are free.”

Chinese filmmakers work under close supervision from the Film Bureau of the State Administration of Radio, Film and TV. Getting permission to shoot or distribute can often be a frustrating process.

A couple of years back, the system was changed so helmers could get script approval before making a film instead of facing a ban once the final product had been cut. But the process remains murky area and an impediment to co-productions with foreign shingles.

Political and sexual content is generally out of bounds, as is satire. Approval for tales of the supernatural is rare, while spy movies are also usually awkward, although that appears to be loosening up.

Many directors simply take their movies abroad to foreign film festivals, although in recent years there are signs that big names such as Zhang Yimou and Chen Kaige have found ways to work within the system.