LONDON: A nurse at the hospital which treated Prince William's pregnant wife Catherine was found dead on Friday, days after being duped by a hoax call from an Australian radio station, the hospital said.

The private King Edward VII hospital named the nurse as Jacintha Saldanha, who had worked there for four years, and said it had learned of her “tragic death” with “very deep sadness.”

The hospital did not comment on media reports that she had committed suicide, while police said they were treating the death, which happened at a property near the hospital, as unexplained.

“We can confirm that Jacintha was recently the victim of a hoax call to the hospital. The hospital had been supporting her throughout this difficult time,”the hospital said in a statement.

“Jacintha has worked at the King Edward VII's Hospital for more than four years. She was an excellent nurse and well-respected and popular with all of her colleagues.

In what it billed as the “biggest royal prank ever”, two presenters from Sydney's 2Day FM station called the hospital on Monday pretending to be Queen Elizabeth II and William's father Prince Charles.

They asked to speak to the former Kate Middleton and a hospital receptionist then put them through to a nurse who gave the presenters private details of the Duchess of Cambridge's severe morning sickness.

Hospital chief executive John Lofthouse added, referring to the nurse who died: “Our thoughts and deepest sympathies at this time are with her family and friends. Everyone is shocked by the loss of a much loved and valued colleague.”

A Scotland Yard spokesman said: “Police were called at 9:25 am (0925 GMT) this morning to reports of a woman unconscious at an address in Weymouth Street, W1.

“London Ambulance Service attended and a woman was pronounced dead at the scene. Inquiries continue to establish the circumstances of the incident. The death is being treated as unexplained.”

A source in the emergency services told AFP that while the death was being treated as unexplained it was not thought to be suspicious.

There was no immediate comment from St James's Palace, the official residence of William and Kate.

Radio presenters Mel Greig and Michael Christian apologised earlier this week for the call, even as the station was milking the publicity for it.

“We were very surprised that our call was put through. We thought we'd be hung up on as soon as they heard our terrible accents,” the presenters said in a statement.

“We're very sorry if we've caused any issues and we're glad to hear that Kate is doing well.”

The presenters insisted it was lighthearted and even Prince Charles joked about the incident on Thursday, saying to reporters who were asking him about Kate's condition: “How do you know I'm not a radio station?”

Kate was admitted to hospital on Monday with acute morning sickness and left on Thursday, saying she was feeling much better.

Her admission to hospital was the first the world knew of her pregnancy. It will be the couple's first child and will be third in line to the British throne after Charles and William.