Chief of the Defence Force Air Chief Marshal Angus Houston has confirmed a group of Afghan fighters were brought to Australia for military training.

But questions remain over whether the group has links to a supposed Afghan war lord.

Air Chief Marshal Houston has confirmed the men were in the country and were trained by Australian troops.

The Defence Department has also provided more details of what it describes as Exercise Leadership Look.

Air Chief Marshal Houston says training the men is a necessary part of Australia's strategy in Afghanistan.

"If we want to get our act together so we have an absolutely seamless operation, it's absolutely imperative that we train with the people that we're going to be fighting side-by-side with," he said.

In a written statement provided to the ABC, a spokesman for the department says the men are members of the Afghan National Police Provisional Response Company, which reports to the Afghan Ministry of Police.

"Exercise Leadership Look is a training activity involving members of the Afghan Provincial Response Company visiting Australia, at the invitation of the Australian Defence Force, to conduct synchronised training with members of Special Operations Command currently preparing to deploy to Afghanistan," the statement said.

"They are our allies, working on the side of the Afghan Government. They are brave people and like us they want to rid Afghanistan of the insurgency."

But the statement does not address the question asked by the ABC about claims the men have links to Matiullah Khan, a man said to be a notorious Afghan warlord.

US forces have worked with Khan for years and he plays a major role in providing security for convoys on the region's treacherous highways.

Although he is one of the most powerful figures in Uruzgan province, the Dutch forces refused to deal with him.

Professor William Maley is the director of the Asia Pacific College of Diplomacy at the Australian National University.

He told The World Today "Muttiallah is a classic example of the wisdom of the old warning that those who sup with the devil should use a long spoon".

"There are degrees of shadiness in Afghanistan but his forces have been accused at different stages of having run extortionate road blocks in various parts of the province and they have even been suggestions that they have engaged in activities to simulate those of the Taliban so as to justify the continued role that they claim to play within the province," he said.

Others think that the practicalities may outweigh other considerations.

Retired Major General Jim Molan commanded Australia's forces in Iraq.

He says war is a dirty business, and the standard for an ally is not always the same as for a friend.

"This is a very difficult one because the moral argument any war has got to be addressed in [is] the issue of what you see on the ground," he said.

"If you go to these wars and if you conduct international relations in fact, with a view that you are not going to deal with anyone who is anyway imperfect, you don't get very far at all and you have got to have a very practical approach to these things and I think that's what we're showing."

He says the coalition in Iraq eventually made a pact with its former enemies, which proved to be pivotal.

"It's not confirmed that they are worse than the Taliban and if you can do a greater good then I think morally you have got to take a risk," he said.

"Now we took an incredible risk in Iraq when we accepted the Sunnis and rearmed the Sunnis as they came back to us."

But Professor Maley cautions against drawing parallels between the two wars. He says the situation in Afghanistan is unique and very complex.

"There are tribal dynamics in Afghanistan which are quite distinct," he said.