The Australian mother-in-law of a notorious Daesh group fighter said Monday she was "devastated" that police had refused to help bring her five grandchildren home from Syria.

Karen Nettleton's daughter Tara is married to Khaled Sharrouf, who gained global infamy last year when he posted pictures of himself and his seven-year-old son on Twitter holding up the severed heads of soldiers.

News emerged last week that Sharrouf may have died in the same drone attack believed to have killed fellow Australian jihadist Mohamed Elomar, raising concerns about what would happen to his children who were taken to Syria last year.

"My advice to the family is to engage with the proper legal authorities and not to conduct this discussion through the media," Immigration Minister Peter Dutton said on Wednesday.

"I think that the Australian Federal Police (AFP) is the natural touch point for the family. I think they need to engage with the AFP and talk about what options there might be."

But Sydney grandmother Karen Nettleton said she had been in contact with the police over a period of months beginning last year about bringing home the children, now aged between four and 14.

"They were saying they would look into helping us get Tara and the children out of Syria," she told the Australian Broadcasting Corporation.

But she added that they suddenly changed their attitude, and concluded they were unable to help her.

"I was talking to one of the agencies and I was told that they wouldn't be able to help us," Nettleton said.

"I was devastated, because, who else do you go to get help to get your children out of a place like that? I certainly can't go there and get them."

The Australian Federal Police said they could not comment on individual cases, but noted that Canberra did not have a consular presence in Syria.

"As such, the AFP is not in a position to provide assistance to Australians who choose to enter this area and seek assistance with their travel from Syria to a safer location," a police spokeswoman said.

"The AFP recognises that family members are concerned for the safety of their loved ones. However, the security and political situations in Iraq and Syria dramatically limit the ability of the authorities to assist in these situations."

Police said they were able, in conjunction with other Australian agencies, to assist Australians who had left Syria and wish to return home.

Tara Nettleton, who converted to Islam and married Sharrouf 10 years ago, took her five children to Syria in 2014.
Source: AFP