The 57-year-old will be sentenced on June 6, pending his background report and a victim’s impact assessment, but the judge refused to assess Cheung’s psychological condition, which would help determine his chance of reoffending. The most the former athlete can be sentenced to by the District Court is seven years.

“The case is quite serious. My preliminary intention is to jail him,” Deputy District Judge Ernest Lin Kam-hung said.

The court heard the victim, identified only as X, told a social worker about the assaults at the time. The worker had confronted her after hearing rumours of the incident and observing that she had been unusually quiet at school.

The intervention led the school’s principal to demand Cheung’s departure in March 1987.

But the woman’s mother had refused to call police because her daughter had left school, and for fear that others might know about the incident. It was not until October 2016, when the woman saw Cheung again on the news, that she reported the case.

Cheung, a former superintendent of the now-defunct Bridge of Rehabilitation Company, drew citywide attention in 2016 when he was spared trial for assaulting a 21-year-old woman in 2014 because she was unfit to testify. She had the mental age of an eight-year-old.

The incident subsequently prompted the Department of Justice to push for a new government bill that would allow the introduction of hearsay evidence in criminal trials to help victims get justice.

Hearsay evidence also played a role in the present case, but most of the prosecution’s allegations came directly from X, who testified via a live television link.

Now 44, she said the first assault took place during lunch break at the school library, after Cheung told her that he would show her medals he had won.

The court heard Cheung was a member of the Paralympic swimming team, with which he had won four medals at the Far East and South Pacific Games for the Disabled in 1982, and a bronze medal at the 1984 Paralympic Games in the 50-metre breaststroke B3.

Having shown her the medals, X said, Cheung then pushed her onto the floor, where he began brushing his lips against hers and grinding his body on hers.

A similar assault took place on the staircase and escalated at an activity room, where Cheung slipped his hand into her underwear to rub her genitals.

Cheung further groped X’s breasts when he taught her to swim at camp, and hugged her very tightly in the shower room.

Though X could not recall all details of the various incidents, the judge found she had been an honest witness who gave clear and unwavering evidence even under intense cross-examination by the defence.

Lin also dismissed the defence’s criticisms of X’s ability to identify, since both eye experts in the case agreed she was capable of seeing within close distance despite her visual impairment, and that her other senses would be more developed.

The judge further rejected Cheung’s evidence, which he found had been organised and tailored to fit the prosecution case.

In particular, Lin observed Cheung had exaggerated his own visual impairment to the extent he effectively claimed he was blind and needed help getting into the pool, when in reality he could identify actors in an identification parade, and walk from the dock to the elevated witness box without any aid.

“Why would he lie like this?” the judge said. “The court believes he was hoping to use this excuse to exonerate himself.”

Cheung had a clear record, but his social worker registration was permanently revoked last year in light of the 2016 case.