Melvin Wong Gam-San http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng

He is not credited in the movie but was credited in HKFA. He is not seen in the movie.

How shd we treat such case?

Is it possible to check the video credits? Or is that what you meant?

I watched the movie on cable. End credit has a list of actors and their roles. Melvin is not included.

The only other reference source that lists Melvin Wong that I can find is mtime.com, most do not. Perhaps HKFA mistook Front Page ,i.e., New Private Eyes, in Chinese, for the original Private Eyes. I could dig out my old LD but it's probably the same as what you watched.

Maybe Wong appeared in the original cut of the movie and later that scene was deleted in the next release of the movie.