Canberra, Australia (CNN)Australian elite forces allegedly killed 39 Afghans civilians and prisoners unlawfully in an environment where “blood lust” and “competition killings” were reportedly a norm, according to a long-awaited official report.

Speaking Thursday, chief of the Australian Defense Force Gen. Angus Campbell said there had been a “warrior culture” among some members of Australia’s special forces serving in Afghanistan.

One alleged incident, the details of which have been redacted to protect the identities of those involved, is referred to in the document as “possibly the most disgraceful episode in Australia’s military history.”

The Australian Defense Force’s (ADF) four-year inquiry into alleged war crimes in Afghanistan alleges that some patrol commanders, who were treated as “demigods,” required junior soldiers to shoot prisoners to achieve their first kill, in a process known as “blooding.” The report presents what it says is “credible information” that weapons or handheld radios were then sometimes allegedly placed by a body to make it seem like the person had been killed in action.

None of the 39 alleged unlawful killings happened in the heat of battle, according to the report, and the Afghans who died were non-combatants or no longer combatants.

Campbell “sincerely and unreservedly” apologized to the people of Afghanistan for the conduct alleged in the report. “It would have devastated the lives of Afghan families and communities, causing immeasurable pain and suffering,” he said.