The Court of Appeal on Friday quashed a decision to jail a former University of Hong Kong professor for life for the murder of his wife and ordered a retrial.

At his trial in 2020, Cheung Kie-chung pleaded guilty to the manslaughter of his wife, Tina Chan, and to preventing the lawful burial of her body.

However, a High Court jury found him guilty of murder.

The court heard that the mechanical engineering scholar strangled her with a cable and transported her body in a wooden box to his office on the university campus in 2018.

Cheung challenged the conviction, arguing that the judge had misdirected the jury by failing to give sufficient weight to his mental state at the time of the killing.

The barrister representing Cheung quoted a defence expert witness as saying that Cheung's judgement and rationality were impaired under extreme stress, adding that the judge had failed to take it into account when instructing the jury.

But the prosecution said the testimony had little impact on the trial.

A panel of three Court of Appeal judges quashed his conviction and ordered a fresh trial.

It will give reasons for its decision within two months.