Around 8.4 million children around the world are enslaved today. Now, in a remarkable journey across three continents, five of them tell their stories. This documentary is presented by reporter Rageh Omaar.
Maloway was sold to help alleviate his family's poverty
Twelve-year-old Mawulehawe has been sold by his mother to a local fishermen in Ghana for $40 (£25).
He may not see his mother again for many years.
She will use the money to buy cooking oil to fry the fish she sells on the shore at Ada, a small fishing town a couple of hours drive east of the capital, Accra.
The fisherman to whom Mawulehawe is sold, Aaron, will take him away to serve a three-year apprenticeship.
Mawulehawe, like many others in the region, is being sold to help alleviate his family's poverty.
He has several brothers and sisters and has had some schooling, but there is not enough money for him to continue. It is now his younger brother's turn to go to school instead.
Mawulehawe insists he is happy with the deal. Fishing has always been part of his life.
And as his family toast the "sale" with a strong drink, it is clear he sees his new life as a new adventure.
While many of the children working on Lake Volta go enthusiastically, most have no idea the dangers that lie ahead.
The long, unregulated hours and dangers such as getting tangled in the nets underneath the water's surface can lead to accidents and fatalities.
The largest number of children found begging in Saudi are from neighbouring Yemen
Six-year-old Ali was picked up by Saudi authorities for begging on the streets of Jeddah.
He was smuggled into Saudi Arabia from Yemen in order to beg.
Ali says he ended up begging after physical abuse involving metal wire attacks on his back. He says he was beaten up when he said he did not want to beg all day.
Ali is one of thousands of Yemeni children sold to gangs and forced to beg each year.
These children are often sold by families who are duped into believing their offspring will get a better life.
Many of the children who are smuggled over the Saudi/Yemen border are beaten and sometimes even mutilated to become better, more effective beggars.
It is hard to be exact about figures, but in 2005 the Yemeni Ministry of Social Affairs acknowledged that about 300 children were crossing the border every month.
RAHUL AND AMIT
Amit (L) and Rahul (R) worked in sweat-shops producing zaris
The Kumar cousins - Rahul, 12 and Amit, seven - thought they were leaving their remote village in the north east of India to go to school and learn a trade.
They had no idea their parents had sent them to one of the most populated cities in the world - Delhi - to work in a sweat-shop.
The boys hated sewing beads on fabric for 18 hours a day.
They lived, worked and slept in the same tiny room and only saw daylight when they were allowed out on Sunday under the supervision of a minder.
Their hands are blistered and their feet deformed because of the repetitive nature of the work. They were beaten and had little food.
Children like Rahul and Amit who work in the zari units are classified as "bonded labourers", often working to clear obscure debts usually incurred by their families.
"Bonded labour" has been illegal in India since 1976 but legislation is largely unenforced and charitable organisations have taken on the burden of investigating illegal labour.
A non-governmental organisation helped the Kumar boys to escape and return home... but the welcome they received was not quite what they were expecting.
Dalyn was rescued from a brothel when she was 13 years old
When Dalyn was only 12 years old, she was tricked and forced into prostitution.
She recalls how she was approached by a woman who asked her if she would like to work at a garment factory in Kompong Cham.
But when she arrived, she was sold to a brothel in Cambodian capital Pnomh Penh for $150 (£78).
Locked in a cage with others underneath the brothel, she was starved, beaten and threatened at gun point until she agreed to service clients.
Many of the children at the shelter where Dalyn is, became infected with HIV or other sexually transmitted diseases after being sold into sexual slavery, and all have been severely traumatised.
Dalyn was rescued by the police and an aid agency but it is only now, at 17 years old and after substantial amounts of therapy, that she feels able to tell her story.
Aid agencies are only able to scratch the surface of the problem of child sex slaves in Cambodia.
In the first six months of last year, of the 186 raids carried out on brothels by the agency, only two resulted in convictions being made.
And in South East Asia alone, Unicef says one million children are involved in the commercial sex trade.
Freddy has been mining since he was six years old
Freddy, 11, is not a slave. He is enslaved by poverty.
He bunks off school to work illegally in a Peruvian state-owned gold mine.
He either sneaks in when nobody is looking, or bribes someone to let him in.
What he finds, he keeps. But the reality is that he finds very little.
He is up at 0500 and works all day.
If he does not find anything, he is beaten by his dad.
There is often no food in the house, so after working all day he begs for food from neighbours or in the street.
Freddy is not alone. The International Labour Organisation has estimated that up to 50,000 children are working in mines in Peru.
Freddy's mine at La Rinconada is located at one of the most inhospitable places on earth - 5,500 metres above sea level.
Conditions are dangerous and miners often die from explosions inside.
Freddy is also at risk from many chronic diseases that could affect him later in life having worked in a mine from such a young age.
This World: Child Slavery with Rageh Omaar was broadcast on Monday, 26 March, 2007 at 2100 BST on BBC Two.