Prime Minister Scott Morrison, citing allegations of "serious and possibly criminal misconduct", appointed the prosecutor to deal with the issue domestically and forestall any move by the International Criminal Court.

Elite Australian commandos were deployed alongside US and allied forces in Afghanistan following the September 11, 2001 attacks.

Since then, a series of often-harrowing reports have emerged about the conduct of Australia's elite special forces units -- ranging from a prisoner being shot dead to save space in a helicopter to the killing of a six-year-old child in a house raid.

The government had initially tried to suppress whistleblower accounts of the alleged wrongdoing, with police moving to investigate reporters involved.

Meanwhile, the Inspector-General of the Australian Defence Forces had conducted a four-year probe into what it called "rumours and allegations" of "possible breaches of the Law of Armed Conflict".

That probe identified 55 separate incidents, most relating to the unlawful killings of "persons who were non-combatants or were no longer combatants" as well as "cruel treatment".

Morrison said a redacted version of the Inspector-General's report would be released within days.

The appointment of a prosecutor represents an escalation in the legal process and could lead to criminal charges against military personnel.

"Serving men and women and our defence forces, both past and present, share the expectations and aspirations of the Australian people for our defence forces, and how they engage in their conduct," Morrison said, making the announcement.

"This requires us to deal with honest and brutal truths, where expectations and standards may not have been met," he said.

Morrison said an independent panel had also be set up to improve the culture within the armed forces and oversee the defence response to the inquiry.

The matter first came to public attention in 2017 when public broadcaster ABC published the so-called "Afghan files", which alleged Australian troops had killed unarmed men and children in Afghanistan.

In response, Australian police launched an investigation into ABC reporter Daniel Oakes and his producer, Sam Clark, for obtaining classified information -- even raiding the ABC's Sydney headquarters last year, before dropping the case.

Federal police said prosectors "considered a range of public interest factors, including the role of public interest journalism in Australia's democracy" before deciding not to prosecute.