An image of an Australian soldier on a memorial in Tarin Kowt, Uruzgan province, southern Afghanistan. Picture: Gary Ramage Details emerge of war crimes allegedly commited by SAS soldiers

An image of an Australian soldier on a memorial in Tarin Kowt, Uruzgan province, southern Afghanistan. Picture: Gary Ramage Details emerge of war crimes allegedly commited by SAS soldiers

DEFENCE Minister Marise Payne has defended the work of special forces in complex and chaotic environments while insisting the government is seriously examining claims soldiers may have committed war crimes in Afghanistan.

Senator Payne's comments on Friday follow the publication of allegations raised in a confidential defence inquiry report obtained by Fairfax Media. The inquiry was told of unsanctioned and illegal application of violence on operations and disregard for human life.

The most disturbing part of the report details an incident in which an Australian special forces soldier allegedly kicked a handcuffed Afghan detainee off a cliff.

Fairfax stated the man, Ali Jan, was a shepherd and father of seven who had been rounded up as part of a search for a rogue Afghan National Army sergeant who had killed three Australian soldiers.

In handcuffs, Jan was kicked off a cliff above a river bed by an unnamed Australian soldier and later executed, Fairfax reported.

Senator Payne said special operations troops operated in complex, chaotic and very dangerous environments to defend Australia's freedoms.

Defence Minister Marise Payne said the allegations are being investigated. Picture Kym Smith

"As Australians would expect, these allegations must be - and are being - thoroughly examined, independently from the chain of command," Senator Payne said in a statement.

She confirmed the inquiry started in May 2016 at the request of the chief of the army and the direction of the chief of the defence force.

She said the government would respond to any recommendations made by the inquiry.

The Special Air Service Regiment is based in Foreign Minister Julie Bishop's Perth electorate.

"I regard soldiers of the SAS as some of our finest," Ms Bishop told reporters in Melbourne.

"These are men who are prepared to put their life on the line in conflict situations to defend us and defend our freedoms."

Former special forces soldier turned Liberal MP Andrew Hastie said the allegations should be taken seriously.

Mr Hastie, who served three tours in Afghanistan, said he had confidence in the report.

But he declined on ABC radio to comment on specific allegations or the culture.

Labor defence spokesman Richard Marles said the opposition would seek a private briefing about the report.

"Our soldiers, particularly our special forces, work in difficult and complex environments," Mr Marles said.

"It's important that we know, as a country, that they're doing it in a professional and legal way." He said information in a report of this significance should not be coming to light via leaks to newspapers.

He called for aspects of the report to be made public.

The inquiry was commissioned two years ago by the then head of the SAS and compiled by a consultant who interviewed soldiers and other defence personnel. The Defence Department said another investigation by the Inspector-General of the Australian Defence Force would make recommendations on how to deal with the claims.

Amnesty International Australia called for transparency.

"There are mounting questions around the (Australian Defence Force) breaching international human rights law," spokesman Tim O'Connor said.