Joining jihad: Australians who have gone to fight in Iraq and Syria

Three Australian members of Islamic State in the Middle East are in talks with the federal government to make their way back home, despite fears the trio could pose a danger to embassy staff who would arrange their return.

The secret talks began several months ago for at least two of the men. No decision has been made about allowing the men back home, although negotiations are ongoing.

Authorities fear the men's claim to have abandoned Islamic State may not be genuine and that the trio will pose a terror risk in Australia if they are allowed to return.

However, chief among the government's concerns is the immediate danger the men could pose to embassy staff who would arrange their passage home.

One source told Fairfax Media authorities fear the men could arm themselves with bombs or other weapons at the beginning of their journey home.

A former health worker from Victoria, believed to be named Abu Ibrahim, is reportedly among the three men wanting to return after becoming disillusioned with jihad.

Melbourne-based lawyer Rob Stary told Fairfax radio station 3AW on Tuesday he was representing a Victorian man in the matter, but would not confirm his client's name.

He said his client, an Australian-born convert to Islam, was prepared to face the full force of the law upon his return and wanted to use his experience to discourage would-be jihadists from joining the terror group.

"Firstly, if he comes back he will face whatever offence he is alleged to have committed and he'll be dealt with according to law here," Mr Stary said.

"We're not naive enough to suggest that he receive any indemnification, or that he should not be charged with appropriate offences. If he's engaged particularly in combat, or militarily in any way, then there's an expectation he'd be charged."

Mr Stary said his client was a trained medic who began working in a camp controlled by the Free Syrian Army, or an offshoot of that organisation.

"Now he says, 'I've seen what I've seen and I want to return home', and we're just trying to engage federal police particularly in a program that might see him provide some benefit to the community here, both in terms of de-radicalisation and probably intelligence," Mr Stary said.

"If he's capable of reclamation then we should utilise him, we should at least engage in the discussion, but the shutters have been put up by the [Australian Federal Police].

"I don't know what the intelligence community knows about him, [but] we know there has been an 'adverse assessment' of him. I'm certain the intelligence community would want to speak to him."

A man named Abu Ibrahim told US broadcaster CBS in April that he wanted to leave the caliphate after becoming increasingly disillusioned by the executions of Western aid workers and journalists.

"A lot of people when they come, they have a lot of enthusiasm about what they've seen online or what they've seen on YouTube," Mr Ibrahim told CBS.

"They see it as something a lot grander than what the reality is. It's not all military parades or it's not all victories."

The man spoke to CBS on the condition his voice be disguised, but his Australian accent is apparent during the television interview.

It is understood lawyers for the three men, including Mr Stary, are trying to determine what penalties or jail terms their clients would face if they returned to Australia.

As recently as Monday, Prime Minister Tony Abbott warned Australian jihadists of the penalties awaiting them should they return home.

"If you do go and try to come back, as far as I'm concerned, you will be arrested, you will be prosecuted and you will be jailed," he said.

Mr Stary said his client was effectively stateless, as all his travel documents had been suspended. "It's his family that have engaged me to try to help him return," he said.

He said he had been in communication with his client, but had not spoken to him directly.

Returning jihadists could face up to 25 years prison if found to have fought with a prescribed terror group, or found to have been in areas of Syria and Iraq banned under new anti-terror laws.

Offences include being a member of the listed terrorist organisation, directing its activities, recruiting for, training or receiving training from the organisation, getting funds to, from or for the organisation, providing support to, or associating with the terrorist organisation.

During his time with IS, Mr Ibrahim told CBS he witnessed crucifixions.

In December last year, he saw a couple convicted of adultery stoned to death.

"It was done publicly," Mr Ibrahim said.

"There were many hundreds of people there who observed. Seeing someone die is not something anyone would probably want to see, but having the actual sharia established is what many Muslims look forward to."

Mr Ibrahim said he joined IS because he wanted to live under strict sharia law, but said life under the caliphate was not what he had envisaged.

"My main reason for leaving was that I felt that I wasn't doing what I had initially come for and that's to help in a humanitarian sense the people of Syria," he said.

"It had become something else. So, therefore, it no longer justified me being away from my family."

It is understood Mr Ibrahim has managed to return to the relative safety of Turkey but other IS defectors have not been so fortunate.

Melbourne teenager Irfaan Hussein may have been beheaded by IS militants in Syria after trying to return home. Mr Hussein, 19, was reportedly killed in March.

Human Rights Commissioner Tim Wilson told 3AW on Tuesday the three men should be allowed to return home.

"They have a right to come back to Australia, but the government also has a right to arrest them at the border, because they've committed a crime, and that's the question," he said.

"They … are wary of coming back, they're worried they'll face penalties. At the current rate they will, and so that's got to be part of the discussion and the negotiation."