China's Film Bureau has blocked the filming of a Hollywood movie about an American investigating a friend's death in Japanese-occupied Shanghai.

The filmmakers have been ordered to make changes to the script and reapply for permission to film if they want to shoot in Shanghai, said Luan Guozhi, director of international cooperation at China's Film Bureau, Wednesday.

Chinese actress Gong Li, shown in December 2006, is slated to star in the Hollywood film Shanghai.
(Chiang Ying-ying/Associated Press)

Neither he nor the film's producers, the Weinstein Co., would reveal details about China's concerns with the script.

The film, Shanghai, is slated to star John Cusack, Gong Li and Japan's Ken Watanabe.

Producer Mike Medavoy described Shanghai as similar in feel to the 1942 Oscar-winning movie Casablanca.

"It's a story of a man who comes to Shanghai to find that his really good friend that he's known for a long time has been murdered. It's (about) the intrigue within that story," he told the Associated Press.

While investigating the death, the man falls in love and uncovers a wider plot involving government secrets.

The film bureau's decision highlights the difficulties of organizing a shoot in China, where plans must be approved by government authorities.

Director Mikael Hafstrom has been in China since September preparing for the movie, Hollywood trade publication Variety reported, and hundreds of thousands of dollars have already been spent planning the shoot.

Hafstrom now says he may move the shoot to Hong Kong where movie lots are already experienced in replicating Second World War-era China.

China is sensitive about portrayal of Japanese-Chinese interactions because of Japan's brutal occupation of the country during the Second World War.

However, sexual or political themes can also trigger the censors.

Taiwanese moviemaker Ang Lee had to cut 15 minutes from his Second World War espionage film Lust, Caution to get the movie shown in China.

With files from the Associated Press