Kelvin Tong's horror thriller Rule Number One is set to start principal photography in Hong Kong next Wednesday (September 19), making him the first Singapore director to cross over to mainstream Hong Kong cinema.

Two Singaporean production outfits - MediaCorp Raintree Pictures and Scorpio East Pictures - and Hong Kong 's Dream Movie Entertainment have boarded the $2m movie alongside Hong Kong-based Fortune Star Pictures.

However, Singapore 's Media Development Authority (MDA) and InnoForm Media are no longer attached as previously announced.

The main cast is toplined by Hong Kong 's Shawn Yue and Ekin Cheng along with Singapore TV actress Fiona Xie. The story follows how the police department deals with supernatural forces.

Shot entirely in Hong Kong and in its lingua franca Cantonese, the picture will see Tong work with a Hong Kong production team including DoP Keung Kwok Man (Protege), art director Horace Ma (Mr Nice Guy) and line producer Candy Leung (who worked on the shoot of Mission: Impossible 3 in Hong Kong).

'Rule Number One has a compelling premise and we hope that the various partners involved in this film project will help make this movie another break-out for Kelvin and for the Asian film industry,' said Daniel Yun, managing director of MediaCorp Raintree Pictures.

Yun is executive producing alongside Fortune Star's Peter Poon, Scorpio East's John Ho and Dream Movie's Gary Lau. A wide release across Asia is expected in March 2008.