LONDON -- British police have contacted Australian authorities about a possible investigation into a radio station's hoax call to a U.K. hospital about the Duchess of Cambridge, they said Sunday, as the company that owns the station promised it is reviewing its broadcast practices.

The prank took a dark twist Friday with the death of nurse Jacintha Saldanha, a 46-year-old mother of two, three days after she unwittingly accepted the call about the health of Prince William's pregnant wife, Kate. The death has sparked an angry backlash from those who argue the Australian DJs who carried out the hoax should be held responsible.

The board of Southern Cross Austereo had an emergency meeting Sunday to discuss a harsh letter from the hospital that fell for the call. King Edward VII's Hospital, where the former Kate Middleton was being treated for acute morning sickness this week, condemned the "truly appalling" hoax and called the consequences "tragic beyond words."

Max Moore-Wilton, the chairman of 2DayFM owner Southern Cross Austereo, said in a letter to the hospital's chairman Sunday that the company will co-operate with any investigation.

"It is too early to know the full details leading to this tragic event and we are anxious to review the results of any investigation that may be made available to us or made public," he wrote. "I can assure you we are taking immediate action and reviewing the broadcast and processes involved."

"As we have said in our own statements on the matter, the outcome was unforeseeable and very regrettable," he wrote.

Australian police Sunday confirmed they had been contacted by London police and said they would co-operate.

The radio station callers impersonated Queen Elizabeth II and Prince Charles and received confidential details about the former Kate Middleton's medical information. The call was recorded and broadcast.

Police have not yet determined Saldanha's cause of death, but people from London to Sydney have been making the assumption she died because of stress from the call.

Both DJs involved apologized for the prank before Saldanha's death. Their show has been suspended indefinitely and their Twitter accounts have been taken down after they were bombarded by thousands of abusive comments.

The station has a history of controversy, including airing a segment in which a 14-year-old girl revealed that she had been raped. It also ran a series of "Heartless Hotline" shows in which disadvantage people were offered a prize that could be taken away from them by listeners.

The Australian Communications and Media Authority, which regulates radio broadcasting, says it received complaints from around the world and is considering whether it should launch an investigation

Separately, Prince William on Sunday pulled out of attending the British Military Tournament, billed as "the largest display of military theatre in the world", citing Kate's illness.

Officials from St. James's Palace have said the duchess is not yet 12 weeks pregnant. The child would be the first for her and William.