Australians Khaled Sharrouf and Mohamed Elomar, who have shocked the nation and the world with their bloody exploits with the Islamic State terror group, have reportedly been killed in Iraq.
The federal government said on Monday night it was working to confirm the deaths, which the ABC said were believed to have happened in the Islamic State stronghold of Mosul in the country's north.
While there is little ground fighting in Mosul, coalition air strikes are being carried out in the area. This raises the possibility that the two men were targetted by coalition bombing raids based on precise intelligence, or were killed incidentally in raids aimed at other targets.
The friends from Sydney have gained notoriety with their violent rampage across strife-torn Syria and Iraq, the macabre details of which have been splashed across social media.
Sharrouf appalled the world when he posted a picture of his young son holding the severed head of a Syrian soldier in the city of Raqqa.
They are also believed responsible for executions of captured Iraqi soldiers – pictures of which have also been put on the internet – and of keeping minority Yazidi women as sexual slaves.
Government and security sources said they had heard of the deaths from within the Lebanese and Muslim communities in Sydney but had not verified them independently.
Foreign Minister Julie Bishop said agencies were working to confirm the reports.
"Our security, law enforcement and intelligence agencies are working to verify the reports about the two men but, of course, information is very difficult to come by in a conflict zone."
The reports come on the eve of the government unveiling its new plans to strip terrorist dual nationals of their Australian citizenship. The Abbott government is expected to introduce legislation on Wednesday.
Coalition fighters have been pounding Islamic State targets around Mosul in recent weeks. International news reports say that dozens of militants have been killed.
The ABC cited a source close to the Sharrouf and Elomar families saying that the men had been killed in a drone strike. Another source told the network they were killed within the past week.
Fairfax Media has been told that Australian authorities would request a targetted strike on militants such as Sharrouf and Elomar if precise information about their whereabouts was known.
Recent statements from the US Pentagon list dozens of airstrikes over the past week in and around Mosul.
The Australian Federal Police issued arrest warrants for both Sharrouf and Elomar in July last year after Elomar appeared on pictures posted on Twitter holding up severed heads.
Recently, Sharrouf's wife Tara Nettleton has expressed interest in bringing their children back to Australia from Syria, where they are believed to be.
Sharrouf and Elomar travelled to Syria in 2013 and then onto Iraq. Sharrouf, despite having served four years in jail on terrorism offences, slipped out of Australia on his brother's passport, a debacle which led to tighter airport security procedures.
The pair were friends in extremist circles in western Sydney before they set off to become fighters for Islamic State. Their activities and those of other hardcore Australian extremists have helped drive significant changes to the nation's counter-terrorism laws over the past 12 months.
