I used to watch this anime in Cantonese back in the 90s, I think it was an late 80s/early 90s anime.
Very vague description, but I also recalled it to be hilarious. I'm unsure of it was popular enough to remain in today's anime.
Modern setting (Japan? 90s anyway)
Main char has 80s style hair, black. Similar to http://yuyuhakusho.wikia.com/wiki/Kazuma_Kuwabara
A minor pervert (or whatever was cut/changed from the JP version; possibly a major one)
Has a regular/female main char whom he always makes perv remarks on (and gets smacked for it as a result)
Solves crimes... I think? I don't recall him being a police, but I recall the use of guns
It probably is more of a slice of life anime than anything significant; no aliens, mechas, or anything :: but I didn't watch that many episodes either
It's rather realistically drawn; similar to Slam Dunk, things only look deformed for comedy purposes
I realise it's probably a very vague/general description, but I can't think of anything else to go on. I'm sure it's actually anime as there's no way China could produce such things.
Fire away!