Will Collett's troubles began with a group of terrorists.

Key points: Police officers whose mental injuries prevent them from working are often forced to go to court to be compensated

Police officers whose mental injuries prevent them from working are often forced to go to court to be compensated The federal Auditor-General has found the compensation process can exacerbate trauma and delay recovery

The federal Auditor-General has found the compensation process can exacerbate trauma and delay recovery The AFP says it is trying to overcome the "stigma" that prevents officers from talking about their well-being

In 2010 he was an Australian Federal Police (AFP) officer on assignment overseas when he became caught up in a dangerous situation with Islamic extremists.

"What they were doing was asking you, as a foreigner, to take their photo and then they would ask to get a photo of you with them," he said.

"And then they'd find out your address, and then come around and cut your head off.

"I had a run-in with these people. It was not a major incident … I dealt with it, moved through it and carried on as such."

He was drinking with old school friends a week later when someone began bragging about living in the country from which he'd just returned.

Even now, Mr Collett struggles to explain his reaction.

"I threatened to cut his head off — I just lost the plot. It was just a rage that came out of me," he recalled.

"And whilst I didn't do anything — I realised the next morning I had better keep a lid on that.

"That was something new — I hadn't been there before."

When the mind 'falls over … or blows up'

The former commando joined the AFP's international deployment group in the turbulent aftermath of the September 11 attacks in 2001.

It was elite, covert and dangerous work, often outside Australia.

"There was a demand for a discrete [counter-terrorism] role … I was enthused by the opportunity and felt it was the way I could contribute to the greater cause," he said.

The physical dangers were obvious. But, as Mr Collett learned, they weren't the only threat.

In 2017, he was diagnosed with post-traumatic stress disorder (PTSD), after years of being exposed to traumatic situations in Australia and overseas.

"I went from normal to feeling like I had a truck sitting on my chest. I was embarrassed, I was ashamed.

"I'd helped a lot of mates who'd had PTSD, but I'd never put myself in that basket."

After he was assessed psychiatrically, he won a claim from the government's workplace insurer, Comcare, which gave him an income because he was unable to work.

One doctor, he said, had likened the mind to a filing cabinet. Normal people encounter a drama, deal with it, file it, then move on.

Mr Collett says he had many friends with PTSD but never thought he would suffer it himself. ( ABC News )

"In an environment like the AFP, that can be a constant — dealing with maybe two or three things a day, it might be five or ten, it might be one big massive one," Mr Collett said.

"With PTSD, the filing cabinet gets full … falls over or blows up.

"The body and mind are totally out of your control. It says … screw you, princess — if you don't get off this, you're gone."

After six months, Comcare asked Mr Collett to see another specialist.

"They were looking to end the Comcare process, they wanted me back on the job," he said.

The news devastated him, although ultimately his case was settled.

'They feel abandoned'

Mr Collett's lawyer, David Healey, says the compensation process exacerbates victims' problems.

"They need to prove they've got an injury and they feel unbelieved," he said.

"They feel abandoned by the very agencies they have sought to serve so diligently in their careers."

Mr Healey has personal experience, too — he served in Afghanistan in 2010 and 2011, and was diagnosed with PTSD soon after.

"We were training Afghan police in the provincial training centre in Tarin Kot in Afghanistan, and a rocket came over the fence and exploded," he said.

"I wasn't necessarily blown apart but the shock wave gave me concussion and I was placed in Tarin Kot hospital with some swelling on the brain and spinal injuries."

David Healey (left) is still dealing with the trauma caused by a rocket attack in Afghanistan. ( Supplied )

Mr Healey is still being treated for his trauma, even as he helps others navigate their Comcare claim.

He said some legal cases could last for two years if the dispute ended up in the Administrative Appeals Tribunal.

"This is triple victimisation, triple traumatisation of clients, because they have to go to independent medical experts that we send them to, that Comcare send them to, and then they have to relay their story once they get into the tribunal.

"You'd want people that have served their country to be looked after, but no, it's not always the case."

Mr Healey believed more police officers were needing to fight to get their injuries acknowledged, both by their employer and the courts.

AFP trying to overcome trauma 'stigma'

Their difficulties were noted in two major reports last year, including one from the federal Auditor-General, which noted the Comcare process could exacerbate psychological injuries and delay recovery.

For its part, Comcare says its job is to assess whether a condition exists and whether it was caused by the victim's employment.

Through a spokesman, the organisation acknowledged police officers' concerns.

"Comcare recognises that the process for workers' compensation can sometimes be adversarial. Comcare has trialled and continues to progress alternative dispute resolution initiatives (such as mediation) for appropriate matters."

But the spokesman said Comcare did not order people back to work — that was a decision of employers.

The audit report was critical of many of the AFP's practices and offered a range of recommendations, including the need for better screening and debriefing for officers.

Assistant Commissioner Peter Crozier said all of those measures had been adopted.

"In law enforcement, it's not just possible you might sustain a mental injury — it's inevitable generally, because of the work that we do."

But the biggest hurdle, he said, was stigma inside the force.

"The change of culture is at the core of that, so people actually feel they can come and talk to us about their challenges," Assistant Commissioner Crozier said.

The AFP now has a health and well-being strategy in place, and a compulsory program focussed on improving mental health — for the whole force, not just those deployed overseas.

"It's about very much recognising how you are feeling but also providing others the opportunity to say … 'are you OK?'"