The hospital treating Prince William's pregnant wife Catherine for severe morning sickness admitted on Wednesday it has fallen victim to a hoax call from an Australian radio station.
Presenters from Sydney's 2Day FM station, posing as Queen Elizabeth II and William's father Prince Charles, managed to get through to a nurse who gave an update on Kate's status and she had not experienced any recent "retching".
The private King Edward VII hospital in London, where 30-year-old Kate was admitted on Monday, confirmed that a nurse discussed Kate's condition and said it "deeply regrets" the incident, which happened in the early hours of Tuesday.
"This was a foolish prank call that we all deplore," said the hospital's chief executive John Lofthouse.
"We take patient confidentiality extremely seriously and we are now reviewing our telephone protocols."
2Day FM presenter Mel Greig, impersonating the 86-year-old British monarch, dialled the hospital and she asked the operator: "Could I please speak to Kate, please, my grand-daughter."
The operator replied: "Oh yes, just hold on, Ma'am."
The call was put on hold and Greig's co-presenter Michael Christian asked incredulously: "Are they putting us through? If this has worked, it's the easiest prank call we've ever made.
"Your accent sucked, by the way, I just want you to know."
Greig was put through to a ward where a nurse told her that Kate was "sleeping at the moment and she has had an uneventful night".
The nurse added: "She's been given some fluids to rehydrate her because she was quite dehydrated when she came in. But she's stable at the moment."
Greig replied, "Oh well, I'll just feed my little corgis, then," while two of her colleagues made barking noises in an impression of the queen's corgi dogs.
"So, when is a good time to come and visit her?" Greig went on. "Because I'm the queen so I need a lift down there."
She then asked Christian, posing as 64-year-old Prince Charles, when he could take her to the hospital.
The nurse suggested any time after 9:00 am would be alright, after Kate had "freshened up".
"She hasn't had any retching with me since I've been on duty and she has been sleeping on and off," she added.
A spokesman for William and Kate at St James's Palace said it was aware of reports of a prank call but would not be making further comment.
Kate is suffering from hyperemesis gravidarum, a severe form of morning sickness that affects about one in 200 pregnant women.
News of her pregnancy has ended feverish speculation about a new royal heir that began immediately after her lavish wedding to Prince William in April 2011.
The baby will be the first heir guaranteed to become monarch regardless of whether it is a boy or girl, after a historic agreement among the 16 Commonwealth realms last year to end the centuries-old practice of male primogeniture.