According to HKFA, they are the same.

Danny Ng Chi-Keung / (???) http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng
Ng Chi-Keung (3) / (???(3)) http://hkmdb.com/db/people/view.mhtml?i ... y_set=big5

Pl confirm & update.

I'm pretty certain these are the same guy. This was "sort of" brought up in this thread, but I was off-base a little bit:

viewtopic.php?f=7&t=50508

Although I mistook the text in the opening credits to mean that Danny Ng was also Sonny Chan, which is untrue (as Dennis pointed out). However, I did notice these two Ng Chi-keungs not long after and forgot to add them to that thread. Thanks for bringing it up!

merged. I created the 2nd by error.