Former Catholic school teacher Garry Mulroy has flown out of Phnom Penh, protesting his conviction for indecent assault against children and alleging he was the victim of an extortion racket.

Mulroy had spent the past week in a safe house in the Cambodian capital amid fears for his safety after he was released from prison in Siem Reap, in the northwest, where he was serving a two-year prison term for assaulting six boys.

He was initially charged with engaging in child prostitution, which carries a 15-year term.

However this was dropped after Action Pour Les Enfants (APLE), an NGO that made the charge, dropped legal representation and the prosecuting police officer failed to turn up in court.

“If I had been guilty I would have killed myself without hesitation,” Mulroy told AAP.

“It was horrible, and it’s the most degrading and embarrassing thing to ever be charged with.”

The former Catholic school teacher from Lismore was found guilty of indecent assault, although all the boys testified he had never touched them and the prosecution did not give details of the alleged assaults.

The prosecution and Mulroy’s defence both appealed to a provincial court in Battambang, where judges upheld the acquittal and reduced his two year sentence to one year plus one year suspended.

He had already served 15 months and was allowed to walk free.

Mulroy has spent the past year in Siem Reap Prison. Photo: AAP

Mulroy said there was nothing worse than being accused of being a pedophile, and vowed to appeal the indecent assault conviction.

He said that verdict was reached to save face among Cambodians who had tried to extort about $100,000 from him.

Mulroy’s release was shrouded in secrecy amid fears of retribution after an independent report commissioned by the defence outlined a litany of miscarriages of justice and rivalries between NGOs that led to his arrest.

Copies of the report by Australian risk management advisor Ross Milosevic were sent to Australian Prime Minister Scott Morrison, members of his cabinet and the Australian Federal Police.

The report also said police interviews with the boys were not conducted with any adult supervision and made “under extreme duress, intimidation and extortion” to secure charges against Mulroy and were a bid by police, NGOs, judiciary and government officials to extort money.

Mulroy said his troubles began while working at two NGOs where he raised concerns over the misallocation of donor money, which resulted in sponsors halting their support.

He then initiated his own NGO, Education House, with six boys aged 11 to 14.

“Those boys stood up in court and said they hadn’t touched me and I hadn’t touched them,” Mulroy said, adding that guards and other prisoners “knew I wasn’t guilty, they knew it was a money case”.

He said police had wanted him to pay about $90,000 to a lawyer of their choice, while one NGO he had worked for had demanded $12,000. A further $15,000 he had in cash had disappeared.

Mulroy’s cell was shared with 22 to 30 inmates and measured five metres by five metres.

He spent most of his 461 days behind bars searching for clean water.

“Tap water smelt like metal and if you had a sore and it got wet it would fizz-up,” he said.

-AAP