This is one royally tasteless hoax.
The London hospital where a pregnant Kate Middleton is being treated for an acute form of morning sickness was fooled into releasing private information about her condition to a prank caller impersonating Queen Elizabeth II.
King Edward VII Hospital has confirmed that a nurse received a call Tuesday from someone who sounded like the British monarch and inquired about the health of Prince Williams expectant wife, and that the staffer provided an update about the Duchess of Cambridge's condition.
The prank call was made by the hosts of an Australian radio show called 2Day, Mel Greig and Michael Christian, who've now posted the conversation on the show's website.
In a statement, a hospital rep tells E! News that the call "was transferred through to a ward, and a short conversation was held with one of the nursing staff. King Edward VII's Hospital deeply regrets this incident." An internal investigation has reportedly been launched.
The hospital's chief executive, John Lofthouse, also adds: "This was a foolish prank call that we all deplore. We take patient confidentiality extremely seriously, and we are now reviewing our telephone protocols."
Meanwhile, a rep for the Aussie program's radio station said: "We apologize for any inconvenience caused."
In the phone conversation, the hosts could be heard speaking with the nurse and inquiring about Kate's condition, to which the staffer replies: "She's sleeping at the moment, and she has had an uneventful night. And sleep is good for her. She's been given some fluids...She's stable at the moment."
Will and Kate announced the pregnancy on Monday, the same day the duchess was admitted to the hospital for hyperemesis gravidarum, an acute form of morning sickness. She's expected to remain under observation for several days.
(Originally published on Dec. 5, 2012, at 6:14 a.m. PT)