Riot officers had stormed the station amid anti-government protests, with TV pictures showing them battering and pepper-spraying numerous people.

Kex Leung, the president of the students' union at Education University, applied to the court for the footage to help him pursue a civil case against the police for damages for assault, unlawful arrest and false imprisonment.

Leung says on the night in question, he had been travelling on a Tsuen Wan Line train towards Central to meet a friend at Prince Edward when he heard announcements saying the station was closed and people should leave immediately.

The student says as he went up an escalator at around 10.50 pm, groups of riot officers appeared above and below him and they were "running amok after passengers, heavily hitting them with police batons, spraying them with pepper spray and subduing them on the ground".

Leung says he was among a group of people who were trapped on the escalator and made to crouch down, and he was left injured after an officer beat him repeatedly on his left arm and hand with a baton, before a number of officers stepped on his back.

He says he was arrested without being told why and was taken along with others on a train to Lai Chi Kok MTR Station before being driven to Kwai Chung Police Station.

Leung says he was only allowed to go to hospital at around 4 pm the following day, and was released unconditionally by the police on September 2.

Judge Anderson Chow noted that the police were not party to this application, and the court was not ruling on Leung's allegations. But he agreed that the CCTV footage from that night should be handed over to the student's legal team, giving the MTR seven days to do so.

"There is no dispute that, if the plaintiff’s allegations against the police are ultimately proved and accepted by the court in his intended civil action, serious tortious or wrongful activities have taken place", Chow said in his judgement.

"I am satisfied that the CCTV footages sought by the plaintiff will likely 'reap substantial and worthwhile benefits' for the plaintiff, in that they constitute a direct source of evidence as to what happened inside Prince Edward Station at the material time of the alleged assault, unlawful arrest and false imprisonment of the plaintiff, and may also enable the plaintiff to identify the individual police officers concerned."

The MTR Corporation had fought the move, saying there was no evidence to show it was mixed up in the alleged wrongdoing.

But Chow rejected the idea that the MTR Corporation was merely a "witness" to the events that night, noting the alleged wrongful acts occurred on its premises.

He added that evidence suggests it was the MTR who called the police to the station and noted that it was the railway operator which arranged the special train to carry those arrested to Lai Chi Kok – a time at which Leung claims he was falsely imprisoned.

"This having been said, I should make it clear that there is no suggestion, and there can be no rational basis to suggest, that MTRC should in any way be held responsible for what happened in Prince Edward Station on the night of 31 August/1 September 2019," Chow said.

He ordered the MTR to provide Leung's lawyers with all the footage from Prince Edward Station from 10.40 pm on August 31 August to 1.30 am on September 1 last year, as well as recordings from Lai Chi Kok Station from 1.25 am to 2 am on September 1.

The lawyers must be allowed to inspect and take copies of the recordings, but the judgement says they are not allowed to disclose the CCTV footage for any purpose other than Leung's civil case against the police.

Leung told RTHK's Damon Pang that he was excited to have secured a legal victory, "even though we all know how our legal system is nowadays in Hong Kong", and said his case could help others get hold of the footage if they want to.

The MTR says it respects the court's decision, adding that it is studying the order to make appropriate arrangements and follow-ups.