A SECRET report has revealed some Australian special forces troops allegedly committed war crimes during our longest deployment in the fight against terrorism.

According to a confidential defence inquiry, Australian soldiers used “unsanctioned and illegal application of violence on operations” extending to a “disregard for human life and dignity”, Fairfax Media reports.

Insiders described internal tensions between different units, a pattern of condescending behaviour towards support personnel, leadership failures, and a culture of drug and alcohol abuse.

“Some of these related to policy, process and governance failure — like loss of weapons, unacceptable WHS (Workplace Health and Safety) practices, poor audit results, injudicious and wasteful practices in resources management, less than transparent or compliant acquisition practices,” the report says.

“Even more concerning were allusions to behaviour and practices involving abuse of drugs and alcohol, domestic violence, unsanctioned and illegal application of violence on operations … and the perception of a complete lack of accountability at times.”

The report claims there are major gaps of knowledge in what the SAS actually does,

The interviewees, who were not named, described a cover-up culture that protected people.

The inquiry was commissioned in 2016 by then-Special Operations Commander Major General Jeff Sengelman, and conducted by defence department consultant Samantha Crompvoets.

According to Fairfax, a senior government official told Dr Crompvoets that former special forces leaders have told them to watch current leaders. “It’s alarming that’s their view,” the official said. “You think ‘What the hell is going on there?’”

The report warns that the current problems faced by the special forces could jeopardise our national security.

“The current situation holds inherent risks, not only for sub-optimal delivery of capacity, but potentially for national security and/or strategic/political interests, given the sensitive nature of deployments.”

Last July, the ABC revealed that a secretive Defence inquiry had been established to investigate the conduct of Australian soldiers in Afghanistan, prompted by the Crompvoets report.

The inquiry was established by NSW Supreme Court judge and Army Reserve Major General Paul Brereton.

The investigation included allegations that Australian soldiers had covered up the 2012 killing and cover-up of an unarmed Afghan boy named Khan Mohammed, and allegations that an SAS member killed an Afghan businessman and planted a weapon on his body.

A third incident, the killing of a man called Bismilah Azadi and his son Sadiqullah in an Australian raid in Oruzgan, was also under investigation.

In a statement to Fairfax, the defence force noted “the IGADF Afghanistan Inquiry has, for some time, been aware of allegations of significant issues involving the Special Operations Task Group in Afghanistan, which are within the scope of the Inquiry”.