The controversial Australian radio station which played a prank call to a nurse at the hospital, where the Duchess of Cambridge was being treated, has said it attempted to contact the King Edward VII Hospital five times to discuss the call before broadcast.
The nurse who took the call and put the presenters through, Jacintha Saldanha, was found dead on Friday.
The pair are no longer on Twitter after receiving abusive messages
The 2Day FM parent company Southern Cross Austereo has cancelled the Hot 30 show and issued a company-wide suspension of prank calls.
Radio hosts Mel Greig and Michael Christian have been suspended indefinitely, but have appeared on two Australian chat shows to discuss and apologise following the tragedy.
The company said in a statement: "SCA and the hosts of the radio program have also decided that they will not return to the airwaves until further notice."
But SCA said while they did not believe the presenters had broken the law or journalism regulation or code, it was "conducting a comprehensive review of company policies and processes".
Lord Glenarthur, who wrote the stern letter to the Australian broadcaster
"Several attempts were made by the production team to discuss the segment with the hospital, but with no success.
"The segment was referred to an internal review process which included internal legal review and authorisation was granted to broadcast."
The DJs gave two interviews to Australia's Channel Nine and Channel Seven. Ms Grieg said she was devastated and "shattered" after Ms Saldanha's death and said: "I have thought about this a million times in my head, that I just wanted to reach out to them and just give them a big hug and say sorry.
"I hope they are OK, I really do."
A recent poll showed Australians believed that the DJs should not be blamed for the tragedy, with almost two thirds of voters in a News Limited poll of more than 11,000 people supporting the pair.
Shares in Southern Cross Media plunged to $1.04, a drop of almost 6 per cent on Friday's close, according to the Herald Sun.