Two Australian disc jockeys have apologized for a hoax phone call that humiliated the hospital treating the pregnant Duchess of Cambridge by tricking a nurse on the ward into thinking she was speaking with Queen Elizabeth.

The call to King Edward VII hospital in London went through in the early hours of Tuesday, giving the DJs a description of Kate's condition and treatment.

Australian radio personalities Mel Greig and Michael Christian — along with their station — later apologized for the hoax.

Australian radio personalities Mel Greig, left, and Michael Christian have apologized for their successful hoax call to London's King Edward VII hospital. (2DayFM)

"We were very surprised that our call was put through," they said in a joint statement. "We thought we'd be hung up on as soon as they heard our terrible accents. We're very sorry if we've caused any issues and we're glad to hear that Kate is doing well."

The hospital admitted it had been victimized by the call from the hosts at Australian radio station 2DayFM in Sydney.

Prince William leaves the King Edward VII hospital where his wife, Kate, the Duchess of Cambridge, was admitted with a severe form of morning sickness in central London on Monday. Two DJs embarrassed the hospital by making a hoax call Tuesday. (Sang Tan/Associated Press)

A woman doing a less-than-perfect imitation of Queen Elizabeth told the nurse answering the phone: "I'm after my granddaughter, Kate. I want to see how her little tummy bug is going."

In the background, a man evidently imitating Prince Charles, soon to be a grandfather, was saying insistently, "Mummy … Mummy …."

The mimicked monarch was told that Kate, who is being treated for acute morning sickness as she and Prince William expect their first child, "hasn't had any retching with me, and she's been sleeping on and off.

"She's sleeping at the moment, and she has had an uneventful night …. She's been getting some fluids to rehydrate her, because she was quite dehydrated when she came in, but she's stable at the moment."

The hospital says it deplored the prank, and its telephone protocols are being reviewed.

"A fair bit of confidential medical information was given over the phone, which of course is now being broadcast around the world, so … very embarrassing for the hospital," said CBC correspondent Dominic Valitis from London.