Four Australian Federal Police officers have killed themselves inside their own workplaces in two years, despite efforts to improve mental health support.

Key points: New rules mean officers need a reason to check out their weapons

New rules mean officers need a reason to check out their weapons Commissioner Andrew Colvin says managing the mental health of officers is a problem 'with no simple solution'

Commissioner Andrew Colvin says managing the mental health of officers is a problem 'with no simple solution' The police union says the new gun rules did not stop another "near miss" suicide, showing they don't work

Their deaths have now prompted tighter firearm rules, such as officers needing a reason to draw out their weapons.

Previously, police were able to check out their guns even while off duty.

The agency's head admitted the changes were prompted by the four suicides — two in the AFP's Melbourne offices and two in its Canberra headquarters within six weeks late last year.

But the national police union said the new restrictions were a bandaid solution that did not prevent another recent "near-miss" suicide.

AFP Commissioner Andrew Colvin said the four deaths had a deep impact and prompted an outpouring of care and support within the agency.

"One officer taking their life is one officer too many," he said.

"These are our colleagues. People we know. People who have been in the organisation, by and large, for a very long time. So it's a difficult time for the AFP."

Two deaths occurred in the Australian Federal Police headquarters, in south Canberra. ( ABC News: Jordan Hayne )

Mental health issues have proven both prevalent and challenging to tackle amongst police.

One in four officers experienced moderate to high psychological distress at any one time, according to a report from post-traumatic mental health support group Phoenix Australia.

This was one of two major reports in the past two years that pulled apart the AFP's mental health and wellbeing strategy and prompted a new one, introduced last year.

They found problems like poor understanding of mental health issues in management, and officers reluctant to self-report struggles.

Also noted were fears of the repercussions for speaking up, due to concerns about confidentiality, their pay and career prospects.

Police known to 'run towards the problem when others run away'

Commissioner Colvin said policing attracted both community-service driven people and "closed people" who often avoid revealing their experiences and troubles.

"That's changing and that's a positive for policing, that we are starting to talk about this a lot more," he said.

"Through tragedy comes opportunities for us to learn; through tragedy comes opportunities for us to get better. I can see within the AFP we are becoming an organisation that is saying, it is ok to talk about this, it is ok to share these experiences, it's ok to admit that you're struggling."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 8 minutes 1 second 8 m Suicide survivors ( ABC North Coast: Samantha Turnbull ) Download 11 MB

He said the AFP had previously been ignorant to the impact and importance of mental health and injury, but had come to realise first responders "can't look after others if we can't look after ourselves".

"But I don't think we were giving it the attention we needed to," he said.

"That was a culture issue, we just weren't thinking these issues through.

"The old adage that police run towards the problem when everyone else runs away, that's in our DNA, that's what we do, so the idea that we should stop and take a break because we're tired, because we're fatigued, because we're having trouble, is so foreign to police.

"That's changing."

'Tough, no-nonsense' attitude part of the problem

AFP chief medical officer Dr Katrina Sanders has worked on a new mental health and wellbeing strategy. ( ABC News: Greg Nelson )

AFP chief medical officer Dr Katrina Sanders said part of the problem was the "tough, no-nonsense" culture that policing traditionally perceived itself as having.

She said this culture had value in a job where emotional resilience and strength were crucial tools in the face of daily trauma, but had needed to shift.

Suicide statistics About eight deaths by suicide occur in Australia each day

About eight deaths by suicide occur in Australia each day The suicide rate of Australian men is three times greater than that of women

The suicide rate of Australian men is three times greater than that of women The suicide rate among Aboriginal and Torres Strait Islander people is more than double the national rate

The suicide rate among Aboriginal and Torres Strait Islander people is more than double the national rate For every death by suicide, it is estimated that as many as 30 people attempt to end their lives Source: Lifeline

"What we do want … is for them to understand what ill health looks like, and what the signs and symptoms of mental health illness or injury are," Dr Sanders said.

"We're normalising physical and mental health. Illness is illness, irrespective of what type of injury you have. And with that comes the presumption that you will recover, and you will return to work."

Dr Sanders said police valued rapport, trust and credibility, and felt more comfortable seeking support from colleagues and mates over doctors.

She said there had been a focus on enhancing emotional skills among officers with the goal to build a self-feeding support network in time.

Changing firearm policies have not fixed the problem, according to the union. ( ABC News: Jordan Hayne )

One of the most immediate changes in response to the deaths has been to restrict officer's access to their firearms, ensuring police were on duty when checking out their gun.

It is a change Commissioner Colvin said most had taken well.

"Nobody wants to be in a situation where their colleagues are taking their own life," he said.

"Nobody wants to be in a situation where their colleagues are getting involved in self-harm. So no, we've got a very mature organisation, we've got very mature police officers and they understand."

Firearm changes didn't prevent another 'near-miss'

Australian Federal Police Association President Angela Smith said the firearm restrictions were a short-term fix.

"It's filled the gap for the moment, but is that the answer?" she asked.

"I know it's not, because we've had a near-miss just recently anyway … restricting people getting to their gun lockers didn't solve it," she said.

Ms Smith called for the AFP to take more notice of what similar agencies were doing elsewhere, like tracking officers' exposure to traumatic jobs.

But Commissioner Colvin said reducing the toll of the work was not easy.

"It's a complex issue in policing, and there is no simple solution," he said.

"I think the risk is we go down a path that sees the next solution as the panacea. It won't be the panacea. It will take time, there's no question about that, but … I know we're making great progress."