A former policeman has been jailed for 10 months for sedition and denied bail pending an appeal after a magistrate found he was unremorseful about mocking a chief inspector’s death and denigrating senior officers in social media comments.

Chui Chun-man returned to West Kowloon Court on Monday to be sentenced on a charge of committing an act or acts with seditious intent by a magistrate who was endorsed by the city’s leader to hear the case.

The 28-year-old former constable was found guilty three weeks earlier of instigating hatred towards the force by praising the untimely death of 14-year police veteran Lam Yuen-yee and saying he wished all “dog officers” would die.

Chui Chun-man returned to West Kowloon Court to be sentenced.

Marine officer 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 in 2021.

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

Chui, then 26, wrote on the force’s official Facebook page that Lam deserved to die and that he wished all “dog officers” would “perish as soon as possible”.

He resigned in early November that year after police began disciplinary proceedings against him.

Acting Principal Magistrate Veronica Heung Shuk-han on Monday said Chui’s actions risked entrenching antagonism against police and exposing officers to the threat of violence by those who harboured ill feelings towards authorities.

She explained that even though the adoption of the national security law had successfully quelled anti-government protests in 2019, there were still safety concerns in the city and that an outbreak of violence remained likely.

The court considered Chui disclosing his profession in the remarks an attempt to establish credibility and his decision to publish the comments on the force’s official Facebook page a “deliberate” choice to be more provocative.

“The defendant insists that he bore no seditious intent in committing the offence. He shows an utter lack of remorse,” the magistrate said.

Defence lawyer Raymond Yu Chiu-cheuk asked for his client’s temporary release immediately after the ruling on grounds including a “reasonable” prospect of winning an appeal in the High Court and a “manifestly excessive” sentence, but Heung refused.

The court heard in mitigation that Chui, who moved from Guangzhou province at the age of 15, had considered being a police officer his dream job and had received 12 commendations during his four-year tenure on the force.

Chui was said to have committed the offence out of impulse after being taunted by a senior officer.

The former constable had lived off his mother as well as his own savings after his resignation, the court was told. He was said to be pursuing a higher diploma with a view to turning over a new leaf.

Earlier during the trial, Chui told the court that he was feeling “grumpy” at the time of the offence and did not genuinely believe in what he wrote on the spur of the moment.

But the magistrate found his explanations unreasonable and said he could not have made such “callous” remarks if he was indeed saddened by the inspector’s death.

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.