THE mother-in-law of Australia's most infamous Islamic State radical Khaled Sharrouf, has told the ABC the Australian Federal Police refused to help her family flea Syria when she pleaded with them last year.

Karen Nettleton, whose daughter Tara is married to Sharrouf, is now asking the Government to help get her daugher and five grandchildren back to Australia, saying they are at risk in Syria.

Sharrouf is believed to have died in a US drone strike. 

In an interview with ABC's 7.30 program,  Ms Nettleton talks about how her daughter became involved with Sharrouf, her granddaughter's marriage to Elomar this month, and her reaction to seeing a photo of her then nine-year-old grandson Abdullah holding the severed head of a Syrian soldier last year.

In a preview released by the ABC, Ms Nettleton talks about seeing her grandson in the now notorious images that shocked the world.

She also reveals that she approached the Australian Federal Police last year to help get her daughter and her five grandchildren out of Syria, but they ultimately could not help.

"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," she said.

Sharrouf's death is yet to be confirmed.

The full interview with Karen Nettleton will air tonight on ABC at 7.30.

The Immigration Minister, Peter Dutton, said he did not think it was helpful for Ms Nettleton to be talking to the media.