Khaled Sharrouf made international headlines in August after posting a photo on Twitter of the couple's 7-year-old son holding a severed head with the words, "That's my boy."
At the time, U.S. Secretary of State John Kerry
said the image was "one of the most disturbing, stomach-turning, grotesque photographs ever displayed."
On Wednesday, Australia's Fairfax media
reported that Sharrouf's wife, Tara Nettleton, was seeking to return home with their children from Syria
. It's believed they have been living in the ISIS stronghold of Raqqa.
When asked how they might be treated on their return, Abbott said: "Crime is crime is crime, and criminals will face the full severity of Australian law, whether they're male or female."
"I'm afraid you don't get off scot-free just because you say, 'I've seen the error of my ways.' If you commit serious crimes, you should face serious punishment, and as far as I'm concerned, that will always be the case."
Concerns about the children
Concern was expressed Wednesday about the fate of Sharrouf and Nettleton's children, who can be assumed to have witnessed violent crimes in Syria, not least the young boy who was encouraged to hold the head.
Nettleton's father, Peter, who hasn't seen his daughter in 10 years, told Sky News: "I still love my daughter and I hope she comes home safely." Asked whether she deserved to be allowed back into the country, he said, "I can't comment -- that's all I have to say."
Earlier this year, it was reported that Sharrouf and Nettleton's 14-year-old daughter
had married his best friend, Mohamed Elomar
, another Australian fighting for ISIS who has posted shocking images of himself posing with corpses.
On Wednesday, Australian Immigration Minister Peter Dutton said parents who exposed their children to such atrocities in foreign wars had "destroyed the lives of their own children."
However, he said that Australia was "a compassionate country that provides support to children in particular who are in need, and the Government will meet their obligations."
Tougher citizenship laws
Australia has taken a tough line with citizens who have left the country to fight for ISIS
On Tuesday, the government announced plans to strip dual nationals of their citizenship if they're found to have participated in "serious terrorist-related activities."
Australian Foreign Minister Julie Bishop told Parliament on Monday that the government had canceled more than 110 passports of people deemed to pose a security risk to the country.
Bishop has long expressed concerns about the risk of "homegrown terrorists," who bring back ideas and skills acquired overseas to Australia for local attacks.
The foreign minister said a precedent was set in Afghanistan, where around 30 Australians traveled to fight with extremists between 1990 and 2010. Bishop said that of 25 who had returned to Australia, "about 19 engaged in activities that were of concern to our security forces after they returned, and eight of them were convicted of terrorism-related offenses."