Line Walker
Undercover police agents lead double lives, until they discover that a mole has been inside the police force. Their world is about to crumble.
Starring Raymond Lam, Kenneth Ma
Watch "Line Walker" on Tubi TV released in 2014. It's a crime and action & adventure show, and has a rating of 7.5 out of 10 from Imdb which is usually fine for this kind of show, and is currently available to watch for free.