Thailand has a reputation for facilitating one of the largest and most visible child sex-trade operations in southeast Asia. The child-protection body, Unicef, estimates the number of Thai children involved in prostitution to be between 60,000 and 200,000. The organisation says the exact number is difficult to enumerate.

As many as 5,000 foreigners travel to Thailand each year to have sex exclusively with children, not to mention the multiple of that figure who travel to the country to have sex with prostitutes of all ages, and who ask no questions about whether they are over 18 years.

The average sex tourist visiting the country is described as being a middle-aged white male from either Europe or North America who often goes online to find the "best deals". A host of websites offer bargains to western travellers who wish to have sex with a virgin.

The US justice department insists that the Thai government often "turns a blind eye" to child sex tourism. This is due to the country's economic reliance on the tourist trade in general, as a boon to its exchequer revenues.

Corruption is also endemic, as in the Philippines.

A report from the International Bureau for Children's Rights said the majority of child prostitutes come from poor families in northern Thailand. Their native communities are referred to as the "hill tribes". With limited economic opportunities and bleak financial circumstances, these families, out of desperation, give their children to "recruiters", who promise them jobs in the city and then force the children into prostitution. Sometimes families themselves even prostitute their children or sell them into the sex trade for a minuscule sum of money. The children live in appalling conditions, according to the report, and in constant fear of beatings by both clients and pimps. The report said that prostitutes as young as 10 years of age can service up to 30 clients a week. They often suffer from numerous sexually transmitted diseases, including Aids.

The US department of justice lists an excerpt from an interview with an anonymous, retired US schoolteacher, conducted on a child sex tourism website, which illustrates the self-deception among sex tourists that is central to their procurement of children and teenage girls for sex: "I'm helping them financially, " he said.

"If they don't have sex with me, they may not have enough food.

If someone has a problem with me doing this, let Unicef feed them."

The situation in Cambodia is no less shocking. A special investigation by BBC correspondent Andrew Harding last year exposed the sale of children to foreign paedophiles for sex.

Many of the country's brothels are run by Vietnamese criminal gangs who ruthlessly suppress any resistance to their business interests. Just as in Thailand, there are strict penal codes making sex with minors illegal, but police corruption is rampant, leaving abused children and sex workers with almost nowhere to seek help.