Don't lose hope.

"You might as well die if you give up hope," he tells AAP as he speaks out about his fight for freedom from Phnom Penh's Prey Sar prison.

On June 3 last year, the Australian was taken by police for questioning after flying a drone over a political rally, sparking a sequence of events which tested the 69-year-old's trademark optimism.

Charged with espionage, the filmmaker was locked up in an overcrowded cell alongside more than 140 inmates with only a sliver of space to sleep.

"I've always been an optimist. All my life. So this was no different," he says.

In the first few weeks, his health quickly deteriorated and he was covered in scabies and sores while losing weight rapidly.

"(At the time) most of my family are concerned that I'm going to die in prison," he says.

Family support - his son Jesse moved to Cambodia with his girlfriend Alex - and a privileged position within the prison system also kept the filmmaker alive.

As a "highly privileged prisoner" he was allowed to take daily breaks outside the cell, using this time to walk and keep fit.

It was this attempt to stay healthy that Ricketson credits with recovering from a life-threatening illness that struck him down in April.

In late August, the filmmaker was convicted of espionage and sentenced to six years following a trial that was widely criticised by human rights activists and politicians in Australia.

A few days later, relief finally came in the form of a royal pardon and freedom.

The only thing Ricketson regrets is the division his imprisonment caused within his family, especially some things he said in the heat of the moment.

"There were some things said and some things written that actually were hurtful," he says.

"But it worked both ways."

His family were split in two camps, one who heeded advice from the department of foreign affairs to remain quiet, and the other camp, who agreed with Ricketson that media attention could help achieve his release.

"That gave rise to family tensions. Some big arguments."

There is one thing his family have all agreed on - his desire to go back to Cambodia is "f***ing crazy".

But banning himself from returning was not simple, because he has adopted family in the country.

"I love them all. And so it's not an easy thing for me to say, 'oh well that's the end of Cambodia'," he says.

"I'm going to do everything I can to go back ... (but) will only go back when I think it's 99 per cent safe for me to do so."

For now, the 69-year-old is considering publishing a book about his experience, but he is keen to get back to filmmaking: "I don't want to get stuck in the role of being a celebrity prisoner."

Australian Associated Press