An ITV investigation has raised fresh concerns that British child sex offenders are finding it too easy to travel abroad and potentially abuse children.
In the first episode of a new series of Exposure, former police detective Mark Williams Thomas goes undercover in Cambodia, a country struggling with its reputation as a haven for child sex offenders.
Posing as a British sex tourist, he meets men who are willing to supply two girls aged nine and ten for $800, or just over £500.
One trafficker describes how he brings children as young as 12-years-old to tourists' hotel rooms.
Williams Thomas also tracks down a British schoolteacher who was jailed by the Cambodian authorities in 2012 for sex offences.
Reginald Blakeley has been put under surveillance by the childrens' charity Action Pour Les Enfants (APLE) on his regular trips to the country.
Secret footage included in the programme shows him swimming with young boys and apparently kissing one of them.
Blakeley denied he was grooming or abusing boys when he was first spotted by APLE in 2010, and insists the police found no evidence of this. No further action was taken on that occasion.
Confronted by Williams Thomas, he says he was the victim of a "scam" and that he was only jailed because he refused to pay the "corrupt fee" demanded by Cambodian authorities.
The charity End Child Prostitution, Pornography and Trafficking (ECPAT) is disappointed by what it sees as the British government's failure to crack down on the problem.
It has accused politicians of failing to deliver on pledges made in 2008 to tighten up the rules on sex offenders travelling abroad.
ECPAT says that Foreign Travel Orders, enabling British authorities to ban offenders from travelling abroad in some circumstances, are still underused.
A Home Office spokesman gave the following statement in response to the Exposure investigation:
Watch an extract of Exposure: Predators Abroad:
Cambodian police are currently involved in an operation as a result of information supplied by Exposure.
Watch Exposure: Predators Abroad on Wednesday 2nd Octoberat 10:35pm** on ITV
Anyone affected by the issues raised in this programme can contact the NSPCC Helpline on 0808 800 5000 or contact the charity via their website