In the Line of Duty 4: Witness_
Two detectives who are up to their necks in trouble and in each other's face, as they try to shut down a drug-trafficking scheme that could be connected with international ties to organized crime. But in the midst of their investigation, innocent immigrant dock worker Luk Wan-Ting gets caught up in the mix when he witnesses the murder of an intelligence operative and is framed for the crime.
Starring
Cynthia Khan, Donnie Yen, Michael Wong
Updated Feb 16, 2026
WHERE TO WATCH
No streaming data available yet.
Check availabilityDROPTHE_ GOSSIP
Cast
Cynthia Khan →
Cynthia Khan stars as Insp Rachel Yeung Lai-Ching in In the Line of Duty 4: Witness.
Cynthia Khan →
Year context
In the Line of Duty 4: Witness was released 37 years ago in 1989.
Overview
Two detectives who are up to their necks in trouble and in each other's face, as they try to shut down a drug-trafficking scheme that could be connected with...
In the Line of Duty 4: Witness is a Action, Crime film with a runtime of 1h 34m.
CAST (18)
Cynthia Khan
Insp Rachel Yeung Lai-Ching
Donnie Yen
Captain Donnie Yan
Michael Wong
Captain Michael Wong
Yuen Yat-Choh
Luk Wan-Ting
Lisa Chiao Chiao
Luk's Mother
Wai Gei-Shun
HK Police Officer
Yuen Shun-Yi
Drug Dealer
Michael Woods
Black Fighter on Rooftop / Motorbike
John Salvitti
Fighter in Alley
SB
Stephan Berwick
Fighter on Motorbike
FR
Fairlie Ruth Kordick
Blonde Fighter
Paul Wong Kwan
Killer at Hospital
Eddie Maher
Loan Shark in Seattle
Liu Kai-Chi
Ming
Paco Yick Tin-Hung
Cho Wing
Jim James
Derek Kwok Jing-Hung
DETAILS
FREQUENTLY ASKED QUESTIONS
What is In the Line of Duty 4: Witness about?
Two detectives who are up to their necks in trouble and in each other's face, as they try to shut down a drug-trafficking scheme that could be connected with international ties to organized crime. But in the midst of their investigation, innocent immigrant dock worker Luk Wan-Ting gets caught up in the mix when he witnesses the murder of an intelligence operative and is framed for the crime.
How long is In the Line of Duty 4: Witness?
In the Line of Duty 4: Witness has a runtime of 94 minutes (1h 34m).
Who stars in In the Line of Duty 4: Witness?
The cast of In the Line of Duty 4: Witness includes Cynthia Khan, Donnie Yen, Michael Wong, Yuen Yat-Choh, Lisa Chiao Chiao.
What is the rating of In the Line of Duty 4: Witness?
In the Line of Duty 4: Witness has a rating of 6.9 out of 10 based on 58 votes on TMDB.
GENRES (2)
Action
Crime
