A BRISBANE man has been charged with child sex tourism offences after allegedly allowing his 13-year-old son to visit a prostitute during a family holiday in Thailand.

It is believed to be the first time laws designed to stop Australian paedophiles preying on foreign children have been used in such a way and the prosecution is being seen as a test case.

The man, 45, was charged by the Queensland Police Service Child Protection Investigation Unit last month and faced Brisbane Magistrates Court yesterday charged with two Commonwealth sex offences which carry maximum penalties of 20 years in jail.

One charge alleges that he caused a child under the age of 16 to engage in sexual intercourse outside Australia, and the other that he procured a child to engage in sexual activity outside his place of residence.

Police allege the offences took place on the Thai resort island of Ko Samui between September 6 and September 9 last year.

The man, who cannot be named, was also charged with assaulting his son causing bodily harm on Brisbane's bayside in February this year.

The man and his lawyer declined to comment outside court, where the charges were adjourned until April 24 for mention.

High-profile Queensland criminal lawyer Bill Potts, who is not representing the man, said it was a "very unique" prosecution.

Mr Potts, of Potts Lawyers, said Australia's child sex tourism laws were designed to stop vulnerable children, especially in Asia, from being exploited.

"The legislation was brought in to give extra-territorial power to Commonwealth criminal law," he said.

"What it means is that it doesn't matter where an offence occurs - if an Australian citizen commits an illegal act in a foreign place, they are deemed to have committed an offence under Australian law and can be punished here.

"People have to be increasingly aware, particularly in matters of morality and sexual offending, that the long arm of the Australian law can extend to wherever in the world an offence takes place."

Mr Potts said while a father introducing his teenage son to sexual activity might once have been seen as a "rite of passage", the sexualisation of children caused significant problems.

"The age of consent is 16 because the law recognises that children need to be protected," he said.

Mr Potts said child sex tourism offences could be difficult to prove due to problems gaining sufficient evidence.

Originally published as Dad charged for son's sex on holiday