A High Court judge on Thursday upheld a ruling of a magistrate who convicted and jailed a 21-year-old student for resisting arrest by police officers during a "shop with you" protest on Christmas Eve in 2019.

The court heard that Lo Chun-sing was subdued by officers in Tsim Sha Tsui's Harbour City after he was seen throwing some pamphlets inside the mall.

Judge Johnny Chan rejected all grounds of appeal, saying the defendant should have expected officers to be around to handle the protest.

He added that it’s "unconvincing" that Lo thought the officer who first tackled him from behind was a gangster or a rioter, as the policeman had repeatedly identified himself.

"Regardless whether the appellant heard police constable A had identified himself, it's impossible for the appellant to mistake him for a gangster or rioter because police constable A had asked him not to run away and stop resisting," the judge wrote.

He said a six-month jail sentence is not particularly heavy and described it as "uncriticisable."

The judge pointed out that the defendant had put up resistance for around a minute or so and required four officers to subdue him – three of whom were injured.