It was the weight of mental illness the AFP commander carried in denial for years.

To the outside world, he was the epitome of success. As a policeman he broke the world's biggest paedophile rings and busted large-scale drug trafficking; as an elite athlete he represented Australia in track and field and competed in the World's Strongest Man contest.

But these achievements seemed a world away as he sat on a patch of grass in an emotional heap, minutes before he was due to compete in the police sporting games.

"I was sitting there, sobbing, and I had no idea why," he said.

"I pulled myself together and went on to win two gold medals and a bronze, because I was good at using sport to mask what was going on in my head."

Exposure to trauma is an unfortunate but inevitable part of being on the frontline, but some are harmed more than others. A shocking one in ten Australian emergency workers have post traumatic stress disorder, while the industry faces a rising trend of suicide. In response to this crisis, and in the hope it will lead to more officers speaking out about their own struggle, this prominent cop has spoken publicly about his mental illness for the first time.

It all started with a visit to his Canberra GP late 2013. Mr Edwards had recovered from a parasite illness he caught during a deployment in Afghanistan, but still feel extremely fatigued.

A long discussion with the doctor ended in a post traumatic stress disorder diagnosis.

"I remember thinking, this can't be me, this is a career killer."

He chucked away the medication and spent the next 18 months in denial, drinking heavily and taking pills to knock himself out for whole weekends.

But it all came crashing down as he was reduced to tears on that patch of grass, before the police games. He had recently flown over to the US after accepting a position as head of the AFP offices in the country. But he took the first flight back to Canberra to finally deal with his PTSD, first opening up to two colleagues.

"Here I was, a copper of 30 years with my sporting career, and I was wearing my heart on my sleeve."

Since joining the AFP in 1985, he had worked in a range of traumatic areas.

But it was the hundreds of child sex offender videos he viewed each week while establishing the AFP's international human trafficking team that had the biggest impact. Many of the abused children were his daughter's age.

"The one that had the most impact was when we received a file from intel and they believed it was an Australian abusing a young girl because they could hear a kookaburra in the video."

"The girl was the same age as my daughter at the time. I didn't want to be around her when she was naked, I would withdraw from her when her friends came over. It really sat with me and got me angry.

Since seeking support, Mr Edwards had mostly recovered from his PTSD. He returned to Washington where he continues to head the AFP offices. What surprised him the most about his journey was never facing the stigma he feared.

"Everyone has been so supportive."

"I've since found out so many high-achievers suffer mental illness. As a police officer you have an inherent mistrust, so it's hard to open up. Then as a male you're just told to suck it up. But people understand that we can't afford to do that anymore."

He admitted that police suicide was vastly underreported.

One improvement he suggested was for the AFP to implement a peer-support program where officers who have experienced mental illness are the first point of contact for others and and direct them to professional support.

"When I first opened up, I didn't know where to go to for help."

"We had programs in place but they were with people I didn't know or trust. You want to know that someone knows what you're going through."

An ACT Policing spokeswoman said there was a range of welfare support available for staff such as "emotional first aid," dedicated welfare officers who support staff and families during difficult times, mental health training, and informal and formal debriefing processes.

Mr Edwards will attend a mental health conference in Washington in June to feed advice back into the AFP's mental health strategies.

"I know many people still suffer in silence," he said.

"But life is precious; we only get one chance."

"We need to let people know the only way out is not to take their life."

For help or information, call Lifeline 131 114 or beyondblue 1300 224 636.