Updated

Australia's prime minister says a 6-year-old Australian boy photographed making an Islamic State movement salute in front of a human body hanging from a cross somewhere in the Middle East is entitled to return to Australia with his siblings.

Prime Minister Malcolm Turnbull said on Monday such children who returned from the battle fields of Syria and Iraq would be subjected to "the closest attention" to ensure Australian are safe.

Australian media have published the photograph posted on social media by Sydney-born convicted terrorist Khaled Sharrouf of his youngest child. The smiling boy holds up an index finger in a salute in front of an apparently lifeless body suspended from a cross with plastic cable ties. A sign hanging from the body said the capital crime was collaborating with Christians.