A unit of elite Australian special forces troops is under investigation for mutilating the body of at least one Afghan insurgent.

The ABC understands the hands were removed from an insurgent's corpse and taken back to the Australian base at Tarin Kot.

The incident occurred during a combined operation of the Afghan national security force and an Australian Special Operations Task Group force in Zabul province on April 28 that resulted in the killing of four insurgents.

At the time, the Australian Defence Force announced only that an investigation was underway.

Key points: Special forces troops under investigation for mutilating insurgent's body

Special forces troops under investigation for mutilating insurgent's body ABC understands soldiers accused of cutting off insurgent's hands for fingerprints

ABC understands soldiers accused of cutting off insurgent's hands for fingerprints Occurred during combined operation in Zabul on April 28, when four insurgents were killed

Occurred during combined operation in Zabul on April 28, when four insurgents were killed Mutilation of bodies of the dead is a violation of the laws of war

Mutilation of bodies of the dead is a violation of the laws of war ADF says it continues to investigate an incident of potential misconduct

The Chief of the Defence Force, General David Hurley, said in a statement released on May 8: "An incident of potential misconduct during the operation has been raised through the internal national command chain."

The ABC understands that the detail of the misconduct he alluded to involves the removal of hands from the corpse of at least one Afghan insurgent.

Australian troops are required to collect fingerprints and eye scans of every Taliban fighter who is killed, if it is possible to do so.

The ABC has learned that an investigator from the Australian Defence Force Investigative Service (ADFIS) lectured a group of special forces soldiers and told them that it did not matter how the fingerprints were taken and that if they could chop off the hands of the dead and bring them back to base for fingerprinting, that would be acceptable.

The ABC understands at least one pair of hands was present at the Australian base in Tarin Kot.

The mutilation or mistreatment of the bodies of the dead is a violation of the laws of war.

Article 15 of the first Geneva Convention says: "At all times, and particularly after an engagement, Parties to the conflict shall, without delay, take all possible measures to search for and collect the wounded and sick, to protect them against pillage and ill-treatment, to ensure their adequate care, and to search for the dead and prevent their being despoiled."

The intelligence team that the instructing sergeant from the investigative unit was working for has now been disbanded, but the matter is being taken extremely seriously by the ADF and by the International Security Assistance Force that has overall command of international troops in Afghanistan.

Since the allegations were made public, Defence Minister Stephen Smith has said that while puzzling and confusing, they appear to be true.

Mr Smith said he and Mr Hurley were shocked by the news, but he does not want to rush to judgement.

"We both found it puzzling, unusual and concerning, so it's not the ordinary course of events that we would expect from the Australian Defence Force or from special forces, but this was a fierce fight, circumstances in extreme, and we don't want to rush to judgement," he said.

"It's difficult for me to prejudge but the available evidence suggest that what is essentially asserted occurred, we now have to try to work out what were the facts and circumstances associated with that."

ADF continues to investigate incident of potential misconduct

In a statement to the ABC today, the ADF says it continues to investigate an incident of potential misconduct involving Australian personnel.

"Members of the ADF operate under strict rules of engagement designed to protect our troops on operations, while ensuring that the actions of Australian forces are consistent with our obligations under Australian and international law in protecting the lives and property of the innocent," a statement read.

"The ADF also takes all reasonable steps to ensure its operations do not breach Afghan customs or cause offence by inadvertently disrespecting religious beliefs or norms.

"Given the public interest in these matters, the Chief of the Defence Force, General David Hurley, issued a media release on 8 May 2013 confirming an investigation was underway.

"However, given the investigation is not complete, it would be inappropriate for Defence to comment further at this time."

Today's statement said the April 28 mission "targeted an insurgent commander responsible for a key insurgent network operating in and around Uruzgan province.

"During the clearance operation, Australian personnel were engaged in a high intensity, complex and dangerous battle," it said.

In announcing the investigation on May 8, ISAF commander General Joseph Dunford said he had informed the Afghan government of the situation.

"ISAF will do a very thorough investigation and if appropriate, we will take action against the personnel involved," he said.

"We take all allegations of misconduct by our personnel very seriously.

"ISAF will fully investigate this incident and keep the Afghan government informed."

Sorry, this video has expired Neil James says Afghan mutilation usual but not necessarily illegal

'Unusual but not illegal'

Neil James from the Australian Defence Association says it is hard to make a judgement on whether the laws of war have been violated until the exact circumstances of the investigation are confirmed.

He also criticised the comparison that has been drawn between the incident involving the Australian unit and American soldiers urinating on corpses.

"If it occurred it would be unusual but it would not necessarily be illegal," Mr James told the ABC.

"In extreme circumstances it would be an authorised action but not contrary to the law.

"You have to gather evidence for court purposes and sometimes it requires unpleasant things to be done but they're perfectly justified in the circumstances.

"Without knowing the exact circumstances it’s hard to comment. This would not necessarily be an illegal act."

Mr James also said it was worth noting that there had been no attempt by the Australian forces to cover the incident up, and that information had been shared through the correct channels,

"This was reported through the chain of command so there is no inference of a cover up," he continued.

"We're fighting people who break the laws of war everyday.

"When you're fighting against somebody that cuts the heads off prisoners - we’re getting a little precious when you think the Australians may have breached the laws of war when they haven’t."

Sorry, this video has expired John Blaxland discusses Afghan mutilation claims

Countering Mr James' point of view however, defence analyst Allan Behm (BEEM) says the Australian special forces unit appears to have violated the rules of war.

Mr Behm says while he cannot comment on the specifics, the latest reports will not be good for Australia's reputation.

"We've got to remember again what we're trying to achieve, our reputation, our integrity," he said.

"The fact that we are fully signed up as an open democratic society, with full respect for the human person, alive or dead let me say. It doesn't stack up with that."

Rudd has 'full confidence' in ADF

Prime Minister Kevin Rudd has also commented on the investigation, saying he has "full confidence in the Australian Defence Force".

"I have full confidence in our men and women in uniform in Afghanistan. I have full confidence in their professionalism," he said.

"If any matters have arisen concerning their conduct then I have full confidence in the chief of defence force's capacity to investigate such matters. That I believe is the subject of his statement earlier today. And as a consequence of that, I believe we should wait for that investigatory process to reach a conclusion."

In 2011, Australian troops were accused of mistreating the corpse of an Afghan insurgent.

Whistleblowers had claimed the insurgent's corpse was put in a taxi with its legs hanging out of the window, in an incident that had become known to troops as the "Weekend at Bernie's" episode – a reference to a 1989 Hollywood comedy in which two men pretend their deceased boss is still alive.

Those mistreatment claims were denied by General Hurley.

Know more about this story? Email investigations@abc.net.au