There is “credible evidence” that Australian elite soldiers unlawfully killed 39 people during the Afghan war, a long-awaited report has found.

The Australian Defence Force (ADF) has released findings from a four-year inquiry into misconduct by its forces. It said 19 current or ex-special forces soldiers should be investigated by police over killings of “prisoners, farmers or civilians” in 2009-13.

The ADF blamed crimes on an unchecked “warrior culture” among some soldiers. The inquiry – conducted by Maj Gen Justice Paul Brereton – conducted interviews with more than 400 witnesses. It also found evidence that:

Junior soldiers were told to get their first kill by shooting prisoners, in a practice known as “blooding”, weapons and other items were planted near Afghan bodies to cover up crimes and an additional two incidents could constitute a war crime of “cruel treatment”.

Afghanistan said it had been assured by Australia that it was committed to “ensuring justice”.

Samantha Crompvoets, an academic who carried out the initial research into the incidents, said they were “deliberate, repeated and targeted war crimes” and said she felt vindicated by the report.

Australia has had forces in Afghanistan since 2002, following the overthrow of the Taliban, as part of a US-led coalition. Initially the international forces’ role was to train Afghan troops but they became increasingly involved in fighting insurgents.

It said 25 special forces soldiers had taken part in unlawful killings directly or as “accessories”, across 23 separate incidents. It recommended that 36 incidents in total be investigated by federal police.

ADF chief Gen Angus Campbell said none of the incidents could be “described as being in the heat of battle”. “None were alleged to have occurred in circumstances in which the intent of the perpetrator was unclear, confused or mistaken,” he told reporters on Thursday.

Gen Campbell said there was alarming evidence that some Special Air Service (SAS) soldiers had taken “the law into their own hands”. “The report notes that the distorted culture was embraced and amplified by some experienced, charismatic and influential non-commissioned officers and their proteges, who sought to fuse military excellence with ego, elitism and entitlement,” he said.
The report said it would be a “gross distortion” to blame senior ADF command, saying the crimes were “commenced… and concealed at the patrol commander level”.

Dr Crompvoets said the incidents “involved in some instances very influential non-commissioned officers”. “Platoon commanders were encouraging or insisting junior soldiers execute prisoners to achieve their first kill, so it was that sort of pattern of behaviour of grooming these junior soldiers for, or initiating them into, the squadron – that’s what was very disturbing,” she told BBC World Service’s Newsday programme.

The inquiry was conducted behind closed doors, meaning few details have been reported until now.