An eight-year-old girl left in a vegetative state following an incident during surgery at Queen Mary Hospital four years ago has died, her family have announced.

Chau Tin-yu was diagnosed with the rare cancer rhabdomyosarcoma in 2018. She never recovered from surgery to remove a tumour in 2020, after a blood transfusion was delayed by 48 minutes.

"Our beloved daughter, Chau Tin-yu, passed away at around 3.40pm on March 10. Holding her pale and cold little hand, accompanied by our family of three, we watched her arrive at the other end of the rainbow bridge," the girl's father said in a social media post on Monday.

"During her last moment before leaving, she used her last bit of strength to open her eyes and look at me and her mother - weak and powerless - then her heartbeat and breathing slowly stopped, until she passed away in peace."

The family had earlier said that Tin-yu's days could be numbered, after her doctor warned her heart was beginning to fail.

Her father said that in recent days, she had not been able to digest food and had been vomiting.

A charity is handling matters relating to the girl's funeral, her father said.