Beast Stalker (Chinese: 証人) is a 2008 Hong Kong action thriller film directed by Dante Lam (who also wrote the screenplay with Jack Ng, and produced with Candy Leung and Cheung Hong-tat).

One day during a police bust with his team who include Sun (Liu Kai Chi), Christy (Sherman Chung) and Michael (Derek Kok).

During a raid, Sun is shot by a fleeing suspect due to an unreliable snitch and Michael failing to act during a door breach.

However complications arise as Ling is suddenly kidnapped by a man seriously damaged in one eye known as Hung King (Nick Cheung) who does shady jobs for hire and has his own agenda.

After Tongg apologizes for his actions in the past, Michael eventually relents and assists Tong track the sim card and also Gao's MMS and contact with the kidnapper revealing Ling is being held in an apartment with Neon Lights nearby.

Derek Elley of Variety wrote, "Crying out for a Stateside remake from its opening reel, stygian crimer Beast Stalker grips like a vise, and is unquestionably the finest Asian action-psychodrama since South Korea's The Chaser last year.

"[1] Neil Young of The Hollywood Reporter wrote, "This glossy, flashily directed plausibility-stretcher picks up whenever the bad guy's unusual character and history are being explored, but flattens out when the focus shifts back from pursued to pursuer.

"[2] G. Allen Johnson of the San Francisco Chronicle called it a new addition to "Hong Kong's great cycle of kinetic action films".