Jim Gamble, the former head of the Northern Irish Police Special Branch posed as a pedophile to investigate the sex trafficking of Cambodian children, for the American TV show “America’s Most Wanted”.

Gamble, the ex-chief executive of the Child Exploitation and Online Protection Centre (CEOP) and "America's Most Wanted" host, John Walsh were "heartbroken and disgusted" when they witnessed a Cambodian bar that hosted between 50 to 60 girls.

Appearing on "America's Most Wanted", which is broadcast on Saturday nights, the shocking scenes that unfold show just how easy it is to pay for sex with an underage girl.

Within two minutes of entering a Cambodian brothel, a madam approached Gamble to ask what he was looking for? When he replied young girls she brought over three or four girls that were estimated to be about 12 or 13 years old.

Playing along however Gamble told her they wanted younger girls. The madam replied: “What do you want? We have six and seven-year-old boys and girls. I can arrange that off-premises.”

Western pedophiles from the United States, Britain and Germany are now known to be traveling east to Cambodia as international sex tourists.  They choose Cambodia, Gamble told the press, because it was cheap to buy a sex slave there.

Walsh said "I saw many Western men that had gone there, not to go to the Buddhist temples, not to go to look at beaches, not to do anything at all but to molest and have sex with children. It's wrong, it's illegal and it has to change.”

The resultant TV episode is being described as a tough show to watch but Gamble insists it's crucial to expose the reality that children are being sexually assaulted by predators, many of whom were from the US.