A piano teacher with autism who molested his five-year-old pupil was sentenced to three years' probation yesterday.

In sentencing, the High Court judge said he had considered the fact that the man, now 23, would suffer disproportionately in prison because of his autism spectrum disorder, among other factors such as his suitability for probation and the progress he has made to reform.

However, Justice Pang Khang Chau further noted that this does not mean that all offenders with autism spectrum disorder should not be jailed, or that the prison service is incapable of taking care of people with the disorder.

Justice Pang said he was simply recognising the "undeniable fact" that a jail term, as the prosecution had originally sought, would have a different impact on the man as compared with other people of his age.

He agreed with the defence's argument that rehabilitation should be the primary sentencing consideration in this case, as the man was a young offender who committed the offence when he was 19.

The man, who cannot be named to protect the identity of his victim, will have to complete 100 hours of community service, and cannot be with anyone below 12 years old without being supervised by his parents or older sibling.

He cannot be employed in any child-related vocations and he is not to access any pornography or sexually suggestive material, the High Court judge ordered.

Prosecutors had originally sought 18 months' jail, while the man's defence counsels from Withers KhattarWong called for probation.

The man pleaded guilty in April last year.

He was teaching part-time at a piano studio when he molested his student on Nov 7, 2016.

He was alone with the girl in the piano studio when he slipped his hand inside her underwear, on the pretext of correcting her posture.

The man scratched the girl around her genital area and continued doing so even after she told him to stop.

The offence was discovered when the girl's mother found her crying in pain in the toilet at home. It took two weeks for the girl's physical injuries to heal, and she had to see a counsellor after the incident.