2Day FM is being investigated by police over the "royal hoax" tragedy.
The investigation could lead to criminal charges if the station is found to have broken the law by recording and broadcasting the prank phone call without permission.
It comes at the behest of Scotland Yard, who asked local authorities to consider "whether any offences were committed under Australian legislation".
Sources say the probe – to be conducted by Australian federal and NSW police – has caught the station off guard.
In February, Britain's Crown Prosecution Service said there was no evidence to support a manslaughter charge.
It also said it would "not be in the public interest" to pursue lesser charges relating to data protection and malicious communications.
"As far as 2Day FM is concerned, they thought all this had been dealt with back in February," the source said.
"They don't understand why this police stuff has emerged seven months [after the prank]."
2Day FM has declined to comment.
In December, hosts Michael Christian and Mel Greig rang a London hospital and duped nurse Jacintha Saldanha into believing they were Prince Charles and the Queen. She transferred their call to another nurse, who divulged private information about the Duchess of Cambridge.
Saldanha subsequently killed herself, blaming the DJs in her suicide note.
On Wednesday, it was revealed Greig has taken legal action against the station for "failing to provide a safe workplace". Legal experts told Fairfax Media she has a strong case and could received "a six or seven figure payout".
Greig has been off air since the tragedy. While still employed by 2Day FM's owner Southern Cross Austereo, it is believed she wants to terminate her contract, despite the company offering her several jobs over the past six months.
Christian has since returned to work and was controversially named the network's "top jock" in June.
The investigation is not expected to affect a looming court stoush between 2Day FM and the broadcasting watchdog, which will be heard in the Federal Court on September 19.
A spokeswoman from NSW Police said: "The Australian Federal Police and NSW Police can confirm a referral was received from the UK Metropolitan Police Service on Wednesday, July 10.
"The AFP will evaluate the referral as per the AFP's usual process to determine if any commonwealth offences are identified.
"NSW police will evaluate the referral to determine if any state offences are identified.
"We will not make any further comment until these processes have been completed."
People seeking support and information about suicide prevention can contact Lifeline on 13 11 14.