Andy Lau, Hong Kong's most famous star, and Bill Kong, the island's most successful producer, are working together on a 3-D gang thriller, the first of its kind among Chinese films.

Lau, 52, invested in, and leads the cast of Firestorm, to be released in December. Producing and jointly investing in the film is Kong, a low-profile tycoon behind hit films such as Crouching Tiger, Hidden Dragon, Hero and Lust, Caution.

The director who won their trust is Alan Yuen, a veteran Hong Kong scriptwriter whose works include the Jackie Chan vehicles Rob-B-Hood and New Police Story.