BBC Radio Five Live has uncovered an international child trafficking ring based in Cameroon with links to Britain.
Children are seen by traffickers as just another commodity
The ring was uncovered when a teenage girl from Cameroon arrived in Nottingham after escaping from a London brothel where she had been forced to work as a prostitute.
Like many other children like her, she began her trip to Britain from the thriving northwest Cameroon town of Bafoussam.
Four years earlier she had been sold as a bride, free from Aids, to a tribal chief.
She was then sexually abused and mutilated. She escaped when a woman offered her a chance to work at a London restaurant.
However, when she arrived in London she was forced to work in a brothel.
Another woman helped her escape and gave her a ticket to Nottingham.
Since her arrival in November, Nottingham police have found four girls and a boy, aged between 14 and 18, abandoned in the city.
It is believed they were brought to the UK to work as prostitutes.
Many of the children arrive in Britain from France, accompanied by traffickers who pretend to be relatives and provide false documents.
Many of the children are taken via Bafoussam
One father in Bafoussam said he cries every day for his missing 14-year-old daughter.
He had persuaded her to work as a babysitter for £10 a month after ill-health forced him to give up his own job as a teacher.
When he visited her after one month, he was told she had run off, possibly back to his home, but has not seen her again, he told BBC's Five Live reporter Sarah Sturdey in Bafoussam.
"I don't even know where Marie Claire is today. I have heard hints that she may be in Europe.
"The family is now divided because of it, because I now know that my family conspired for my child to be sold.
"Each day we cry, we cry when we think of our daughter."
A Bafoussam social worker, who was reluctant to speak but feels that something must be done, said trafficking was like a business, with the girls regarded as just another product to be bought and sold for thousands of pounds.
But it was difficult to deal with the issue as the children and their parents lived in fear.
"Sometimes the parents believe that the child has disappeared through witchcraft, and the parents keep quiet," he said.
Unicef was in talks with Cameroon authorities to find ways to help, including education programmes, particularly family planning to prevent people having large families that they cannot support.
Nottingham vice squad Detective Inspector Ian Winton said the trafficking had spread across the UK.
"The criminal organisation involved to move these people around is very well organised, it is very intricate and takes a great deal of planning."
While selling children into domestic service was a traditional way of bringing up children in West Africa, the system was becoming corrupted, David Old from Anti Slavery International told Five Live.
"Previously children were placed with families close to their own family so that they would see mum and dad regularly but now they are placed further and further away, even across borders and coming to Europe and the UK.
"That breaks down the system."
European governments had begun to take the problem seriously only in the past two years, despite lobbying for at least six years, he said.