The chairman of the Australian radio network at the heart of a hoax call targeting Prince William's pregnant wife has called the apparent suicide of one of the nurses duped by the prank "truly tragic."

"It is too early to know the full details leading to this tragic event and we are anxious to review the results of an investigation," Southern Cross Austereo's Max Moore-Wilton wrote Sunday in a letter to the head of King Edward VII's Hospital in London.

The hospital, where a nurse apparently committed suicide after being duped by two DJs from Australian radio station 2DayFM, has condemned the radio station in a strongly worded letter.

The DJs, impersonating Queen Elizabeth and Prince Charles, called the hospital Tuesday and gained information about the condition of Catherine, Duchess of Cambridge -- which they subsequently played on air.

On Friday, the nurse who transferred the call through to the ward, Jacintha Saldanha, was found dead.

London's Metropolitan Police have contacted Australian authorities in relation to the call, but "are not discussing about what or with who" they're talking, a spokesman told CNN.

A spokeswoman for New South Wales Police in Australia told CNN: "As the investigation into the death of London nurse Jacintha Saldhana continues, New South Wales Police will be providing London's Metropolitan Police with whatever assistance they require."

Southern Cross said all advertising had been pulled from 2DayFM until "at least the end of business Monday" after several large advertisers pulled out.

Ben Barboza, Saldanha's husband, expressed grief over his wife's death in a post on Facebook: "I am devastated with the tragic loss of my beloved wife Jacintha in tragic circumstances, She will be laid to rest in Shirva, India."

Saldanha's daughter posted a photo of herself with her mother and wrote: "I miss you, I loveeee you. Jacintha saldanha."

The chairman of the hospital where the pregnant Duchess of Cambridge was a patient slammed the Australian radio station's decision to broadcast the recorded prank call as "truly appalling" on Saturday,

"King Edward VII's Hospital cares for sick people, and it was extremely foolish of your presenters even to consider trying to lie their way through to one of our patients, let alone actually make the call," wrote hospital chairman Lord Glenarthur.

"The immediate consequence of these premeditated and ill-considered actions was the humiliation of two dedicated and caring nurses who were simply doing their job tending to their patients."

"The longer term consequence has been reported around the world and is, frankly, tragic beyond words."

Lord Glenarthur called on the radio station to take steps "to ensure that such an incident could never be repeated."

The fallout from Saldanha's death has stretched from Britain to Australia -- with questions being raised about how far is too far in the effort to find out details about Catherine's pregnancy.

The two Australian DJs behind the practical joke, Mel Greig and Michael Christian, have come under fire, with some using the phrase "blood on your hands" to condemn their actions on the Sydney-based radio station.

"Pranksters Face World Fury," screamed the front-page of the UK's Daily Mirror on Saturday, while Daily Telegraph columnist Bryony Gordon said it was "not so funny to hear two grown adults call up a hospital ward full of sick people to try to scam information about one of them."

The DJs have since apologized, and "mutually decided" to go off the air for an undetermined period, Rhys Holleran, CEO of the Southern Cross Austereo media group, said Saturday during a news conference.

But he defended the legality of the station's action, saying he was "very confident that we haven't done anything illegal."