HONG KONG: A Hong Kong inquest failed Saturday to determine the cause of a student's death that fuelled tensions between protesters and the city's police force at the height of the pro-democracy rallies that swept across the financial hub in 2019.

A five-member jury at the coroner's court returned an open verdict, voting four to one, after a 29-day inquiry into the case of 22-year-old Alex Chow who died from head injuries following a fall from the third floor to the second floor of a car park near a protest.

Hong Kong was upended by more than seven months of pro-democracy protests in 2019 over moves by Beijing to tighten its grip on the city, and clashes escalated after Chow's death in November of that year.

"I want to tell my son that we have tried our best. Let's see if the truth will be revealed in the future," the student's father, Chow Tak-ming, told reporters outside the court.

In delivering an open verdict, the jury determined that it could not pinpoint whether his death was an unlawful killing or an accident.