PRINCE William and Queen Elizabeth were said to be furious after two DJs tricked hospital staff caring for Kate Middleton – the Duchess of Cambridge – into revealing personal information as she recovers in hospital.
According to reports, Australian radio presenters Mel Greig and Michael Christian of 2Day FM pretended to be Queen Elizabeth and Prince Charles, as they rang the King Edward VII Hospital in London.
A nurse was taken in by the prank and persuaded to give away various personal details, including the best time to call in as staff were about to 'get her freshened up', adding that she was 'quite stable' and had been 'sleeping on and off'.
The prank by the Australian radio station prompted an angry response, sources at St James's Palace said.
William, arrived for a third day at the private hospital in central London at 12.15pm yesterday without acknowledging the world's media camped outside the building.
He was said to be seething over the intrusion into his wife's health, despite the call having a humorous rather than sinister motive.
The 2Day FM presenters were put through to a nurse who reportedly told them: "She's sleeping at the moment and she has had an uneventful night. She's been given some fluids, she's stable at the moment."
The prank call will be deeply embarrassing for the Edward VII Hospital, which is the medical institution of choice for the Royal Family.
A spokesman for the hospital confirmed the call was transferred through to a ward and a short conversation was held with one of the nursing staff.
John Lofthouse, chief executive at the King Edward VII Hospital, said: "This was a foolish prank call that we all deplore. We take patient confidentiality extremely seriously and we are now reviewing our telephone protocols."
The radio presenters, Greig and Christian, were told by the nurse that they could visit the Duchess after 9am.
She told the hoax queen and Charles: "She's quite stable. She hasn't had any retching with me and she's been sleeping on and off."
St James's Palace declined to comment about the prank call.
In 1995 Canadian DJ Pierre Brassard, pretending to be Canadian prime minister Jean Chretien, was put through to the queen. The pair spoke for around 15 minutes and he even managed to elicit a promise that she would try to influence Quebec's referendum on proposals to break away from Canada.
Kate was "continuing to feel better," St James's Palace said.
She has developed the condition hyperemesis gravidarum, which can cause severe vomiting and leave patients feeling tired, dizzy and suffering from headaches, caused by dehydration.
But it now appears she is responding to treatment and is likely to be having less severe bouts of morning sickness.
A spokesman said last night: "The Duchess of Cambridge is continuing to feel better.
"She and the Duke are immensely grateful for the good wishes they have received.
"She will remain in hospital at present and will continue to be treated for hyperemesis gravidarum."
Journalist Brett Mason, the Europe correspondent for Network 10 Australia, said the reaction to the story in Australia was one of shock.
"It's quite extraordinary that two particularly bad royal family impersonators with distinctly Australian accents have been put through," he said.
"I think we're probably having a bit more of a chuckle than our British comrades, who are still trying to see the funny side."
Mr Mason, who was sent to the hospital to cover the story, said he had spoken to one of the radio presenters. "I think they're quietly chuffed that they've made international headlines," he said.
Kate's diary of engagements for this week have been cancelled to allow for the rest she will need when she is discharged.