The report examining the conduct of Australian Special Forces during the war in Afghanistan was released by the Defence Chief General Angus Campbell on Thursday.
The Chief of the Australian Defence Force Angus Campbell has offered a "sincere and unreserved" apology to the Afghan people after a long-awaited report into the conduct of Australian Special Forces soldiers found "credible information" of unlawful killings by some soldiers.
Since 2016, the Inspector-General of the Australian Defence Force has examined allegations of war crimes by Australian special forces in Afghanistan.
Over four years, Justice Paul Brereton interviewed more than 400 witnesses and examined tens of thousands of documents.
In the report, released publicly on Thursday, Justice Brereton disclosing allegations of 39 unlawful killings and two allegations of cruelty involving 25 current of former Defence Force personnel in 23 separate incidents.
A few of the Afghan nationals killed were not participating in hostilities, while the majority were prisoners of war.
The report covered the period from 2005 to 2016, but almost all of the incidents uncovered occurred between 2009 and 2013.
"None of these are incidents of disputable decisions made under pressure in the heat of battle," the report said.
"The cases in which it has been found that there is credible information of a war crime are ones in which it was or should have been plain that the person killed was a non-combatant."
Dozens more allegations investigated could not be substantiated.
Justice Brereton also found there was credible evidence some soldiers carried "throw downs" such as weapons and military equipment to make it appear the person killed was a legitimate target.
As well, there was evidence junior soldiers were required by their patrol commanders to shoot a prisoner in a practice known as "blooding" to achieve their first kill.
The inquiry recommends the Chief of Defence refer 36 matters to the Australian Federal Police for criminal investigation. Those matters relate to 23 incidents and involve a total of 19 individuals.
Releasing the report, General Campbell said he'd spoken to his Afghan counterpart to offer his apologies.
"To the people of Afghanistan, on behalf of the Australian Defence Force, I sincerely and unreservedly apologise for any wrongdoing by Australian soldiers," he told reporters in Canberra.
"Such alleged behaviour profoundly disrespected the trust placed in us by the Afghan people who had asked us to their country to help them."
Justice Brereton placed the greatest blame on patrol commanders, believing they were most responsible for inciting or directing subordinates to commit war crimes.
"It was at the patrol commander level that the criminal behaviour was conceived, committed, continued, and concealed, and overwhelmingly at that level that responsibility resides."
Prime Minister Scott Morrison has previously announced a special investigator will pursue possible criminal prosecutions.
The position is yet to be filled.
The Brereton report recommended administrative action be taken against some serving ADF personnel where there is credible evidence of misconduct, but not enough for a criminal conviction.
It also recommended Australia compensate the families of Afghan people unlawfully killed, without waiting for criminal prosecutions.
"This will be an important step in rehabilitating Australia's international reputation, in particular with Afghanistan, and it is simply the right thing to do."
As well, the inquiry recommended various service medals be stripped away from some individuals and groups.
The Special Air Service second squadron has already been disbanded following the report.
General Campbell said the squadron had been "struck off the Army order of battle" not because it was the only squadron involved, "but because it was at a time one of the squadrons involved in the allegations made".
The report described the allegations as "a disgraceful and a profound betrayal of the Australian Defence Force's professional standards and expectations".
"We embarked on this inquiry with the hope that we would be able to report that the rumours of war crimes were without substance.
"None of us desired the outcome to which we have come. We are all diminished by it."
Prime minister's apology
Afghan President Ashraf Ghani says he received a phone call from Mr Morrison ahead of the anticipated release of a report into alleged war crimes.
In a statement President Ghani said: "The Prime Minister of Australia expressed his deepest sorrow over the misconduct by some Australian troops in Afghanistan and assured the President of the Islamic Republic of Afghanistan of the investigations and to ensuring justice."
In a statement, Mr Morrison confirmed he had called President Ghani "to foreshadow the release of the report today".
"The report contained some disturbing allegations and the Australian government was taking those allegations very seriously.
"The report would be passed to an Office of the Special Investigator to investigate any criminal allegations. So they would be dealt with according to Australian law.
"President Ghani appreciated the direct contact, noted the many Australians who had served with distinction in Afghanistan and said he was counting on Australia’s justice system to follow up on these matters."
With reporting by Rashida Yosufzai, Brett Mason and Jennifer Scherer