The Hospital Authority said on Monday it's investigating the case of a patient believed to have fallen to his death at Princess Margaret Hospital the day before.

Princess Margaret Hospital has listed the incident as a sentinel event and said it will fully cooperate with the police investigation.

In a statement, a spokesperson for the hospital said a 74-year-old male patient was admitted to a medicine and geriatrics ward last Thursday due to hypertension urgency.

He was described as emotionally stable.

The hospital added that the patient appeared calm and acted normal when ward staff measured his blood pressure at around 5pm on Sunday.

But he was soon found to be missing from the ward, with his personal belongings left behind.

The hospital notified the patient’s family as well as the police.

The hospital said it was informed by the police at around 10pm that the patient was found dead after falling from height.

The incident has been reported to the Hospital Authority Head Office and will be investigated by a root cause analysis panel.