A former policeman has been found guilty of sedition for publishing a series of online comments mocking a chief inspector’s death and urging all “dog officers” to die, in what the magistrate called a deliberate and vicious attempt to bring the force into disrepute.

West Kowloon Court found Chui Chun-man guilty of doing an act or acts with seditious intent over remarks he made on Facebook in late September 2021 in relation to the tragedy that befell 14-year police veteran Lam Yuen-yee.

Lam was thrown overboard alongside three colleagues when their vessel was rammed by a turbocharged speedboat they were trying to intercept in mainland Chinese waters on September 25, 2021.

Her body was found two days later, with the force posthumously promoting her from senior to chief inspector in recognition of her service.

Lam Yuen-yee was attached to the Small Boat Division of the Marine Police and had 14 years of experience in the Hong Kong police force when she was killed.

Last year the court heard that just hours after Lam went missing, the then 26-year-old constable wrote on the force’s official Facebook page claiming the inspector “has probably died but she deserves it”.

Police identified Chui via a car registration number shown on his personal account and uncovered more offensive remarks he posted.

In one comment, Chui said: “No one in the police department dies an undeserved death. No doubt death is rightly served on that woman.”

The court heard the defendant described the late officer as “fish”, police slang for floating corpses, while calling his senior colleagues “dogs” and said he wished they would “all perish as soon as possible”.

Police commenced disciplinary proceedings against Chui on September 29 that year and arrested him on November 11 soon after he tendered his resignation.

In the witness box, the former policeman acknowledged he was behind the provocative comments, but insisted he was feeling “grumpy” at the time and did not genuinely believe in what he wrote on the spur of the moment.

Defence lawyer Raymond Yu Chiu-cheuk further submitted his client had been lured into allowing police access to his mobile device.

But Acting Principal Magistrate Veronica Heung Shuk-han found no issue with the way police obtained evidence against Chui, noting the defendant voluntarily divulged his mobile device’s password to investigators during the initial disciplinary procedures.

She found Chui’s explanations unreasonable and said the ex-constable could not have made such “callous” remarks if he was indeed saddened by the inspector’s death.

Lam Yuen-yee is given a police funeral with full honours in November 2021.

Heung also highlighted Chui’s repeated references to “dog officers”, an expression she said was connected to the 2019 anti-government protests, as evidence of his intention to sully the force’s reputation.

“When Inspector Lam’s fate remained uncertain, the defendant issued spiteful comments stating that he wished her dead and that she deserved to die,” the magistrate said.

“His vicious statements showed the hatred and contempt he had for the officer who faithfully discharged her duties.

“I am certain that the defendant, by deliberately choosing to express his disdain, antipathy and disaffection with senior police officers on this open platform, was, instead of expressing his views, trying to provoke and instigate discontent with the police force.”

The magistrate adjourned hearing mitigation submissions from the defence until March 4 and remanded Chui in custody.

Sedition is punishable by up to two years’ imprisonment upon a first conviction.

It has been defined by the city’s top court as an offence capable of endangering national security, meaning defendants can face higher hurdles when applying for bail and their cases may only be heard by judges approved by the chief executive.