This article is more than 2 years old

This article is more than 2 years old

An anaesthetist has been jailed for life in Hong Kong for murdering his wife and teenage daughter using a yoga ball filled with carbon monoxide that he had placed in their car.

Prof Khaw Kim-sun, 53, shook his head and looked at his three other children sitting in court on hearing the verdict on Wednesday, broadcaster RTHK reported. One of them burst into tears.

Prosecutors had told the high court that Khaw, from Malaysia, left the inflatable ball in the boot of a car and the suffocating gas leaked out and killed them.

His wife, Wong Siew-fing, and 16-year-old daughter Lily were found by the roadside in a locked yellow Mini Cooper in 2015 in a case that initially baffled police.

The pair were certified dead at the same hospital where Khaw worked and a postmortem examination concluded they had died from inhaling carbon monoxide. Police found a deflated yoga ball in the back of the car.

Prosecutors accused Khaw – a specialist in anaesthesiology and an associate professor at the Chinese University of Hong Kong – of hatching a murder plot because he was having an affair with a student.

The court heard earlier in the trial that Khaw had told colleagues he planned to use the gas on rabbits. He later told police he had taken it to get rid of rats at home.

The professor told police after his arrest that Lily knew about the dangerous gas in the yoga ball and suggested she may have wanted to kill herself.