An American aviation executive has been sentenced to a decade in jail in Cambodia for sexually abusing girls as young as five.

Brian Naswall, the founder and CEO of Aero Cambodia, was arrested last year, reportedly in the act of abusing three underage girls, and was accused by nine victims between the ages of five and 16.

Naswall, 53, denied the charges during his trial in Phnom Penh's Municipal Court and claimed the case was fabricated, but was today found guilty of engaging in child prostitution.

Brian Naswall, founder of AeroCambodia, arrives at the Municipal Court in Phnom Penh, Cambodia

Naswall (bottom right), walks from a prison van before he was sentenced in Phnom Penh's Municipal Court

Naswall, pictured in a Facebook photo, described himself online as a 'part-time pilot and world traveler'

Action Pour Les Enfants (APLE), a non-governmental organization that hunts down suspected foreign pedophiles in Cambodia, said Naswall was arrested by Tonle Basac police in May 2015.

At the time, the organization claimed, he was engaging in sex with a 12-year-old girl in the presence of two other underage girls.

APLE claimed Naswall lured the girls to a quiet place surrounding Koh Pich Island and sexually abused them with the promise to pay them up to $20 each.

After he was arrested, Cambodia's Anti-Human Trafficking and Juvenile Protection Department took over the investigation.

APLE said it helped police to identify more victims.

'Six other victims had disclosed that they had been sexually exploited on different occasions,' the organization said in a statement released after the sentencing. 'Finally, police had concluded a total of nine victims.'

Naswall, 53, was sentenced to 10 years in prison and ordered to pay $12,000 in compensation to his victims

APLE claimed Naswall was caught in the act of abusing three underage girls when he was arrested

Naswall, whose airline offered sightseeing tours of Cambodia, poses in front of a small aircraft

In its ruling, Phnom Penh's municipal court sentenced Naswall - who was wearing an orange prison jumpsuit and looked slimmer compared to photos on his Facebook profile - to 10 years in jail.

As he was led into court by police officers he gave a thumb's up to photographers.

Naswall, whose company offers joyrides or sightseeing tours in small aircraft for as little as $50 per person, must also pay 48 million Cambodian riel (approximately $12,000) in compensation, which will be split among eight of his victims.

A member of his legal team said he would appeal the ruling.

Vando Khoem, the program director of APLE, called for Naswall to be deported after he serves his sentence.

'I applaud the decision of the court. However, I express my heartfelt disappointment that the court didn’t order his deportation,' Khoem said. 'Without deportation, he would exploit an opportunity to be here to prey on Cambodian children. Deportation should be made automatically.'

On his LinkedIn profile, Naswall described himself as a pilot and world traveler.

He claimed to have previously worked as a locomotive engineer who operated trains in Oregon, Washington, Montana, California and Idaho in the US, British Columbia in Canada, Thailand, Cambodia and Mexico.

Naswall's sentence is the latest effort by officials in the impoverished nation in Southeast Asia to punish pedophiles who travel from abroad and prey on children.

Cambodia's grim reputation as a child sex hub attracted global attention in 2002 when British glam rocker and serial pedophile Gary Glitter was deported over suspected sexual offences.

The country launched a drive in 2003 to shed its reputation as a haven for foreign pedophiles.

Dozens of foreigners have since been prosecuted for child sex crimes but there are still wide gaps in policing.