Secret Executioners(1982)

The story centres around various gang related tribulations plus a long running feud between a scruffy looking detective who spends the entire film shivering as though suffering from Heroin withdrawal symptoms(!) and Hwang who plays his old friend who has clearly landed on the wrong side of the tracks as it were and is now head of a gang called the Yellow Tigers. Throw into this mix a sub plot involving the lucrative ownership of a night club, a woman searching for her missing sister and of course the newly edited in footage which details the hired goons fighting on behalf of the gangs