The BBC has learnt that many of the hundreds of girls from Nigeria sold into sexual slavery in Europe each year have been trafficked through England.

I don't know why it's not getting the attention it deserves because I think that since the slave trade was abolished many years back, it's coming back in a modern form

Eki Igbenedion, Wife of the Governor of Edo State

Towards the end of 1996, two police officers in Hove in Sussex began reviewing old missing persons cases.

Over the coming months Detective Chief Inspector Chris Ambler and Detective Superintendent Dave Gaylor noticed a disturbing pattern emerging.

"There's no doubt this is modern day slavery," says DCI Chris Ambler.

"They are nothing more to the people who are using them than a commodity to make money."

Girls claim asylum in Britain

Young girls were arriving from West Africa and claiming asylum at major British airports.

Because they were under 18, they were then taken into the care of social services and placed in children's homes or foster care.

Within a number of weeks, there would be a mysterious phone call and the girls would disappear.

The detectives established they were then being transported to a number of European countries, in particular Italy, where they were forced into prostitution.

In 1998, the Sussex Police police force launched Operation Newbridge.

With the help of Britain's National Crime Squad, two suspected traffickers have been arrested, and one person deported.

The children's ordeal begins in Benin City in Nigeria is a dusty, sweaty, frenetic and noisy place. Girls and boys are lured into sexual slavery with tales of riches in far-off lands.

Benin City: One of Nigeria's poorer cities

Osamede Iguobaro was just 14 when she was approached at a local market. She was told she would earn big money pleating hair in Italy.

She was smuggled across a number of West African countries to the Ivory Coast where she was sold to a Nigerian woman - a "Madame" based in Italy.

Like so many other teenage girls, she was forced to become a prostitute.

The case is now before a Nigerian court but, even if convicted, the woman who sold her is likely to escape with a fine.

Trafficking is 'routine'

Grace Osakue, the founder of Girls Power Initiative, says the real tragedy of Osamede's story is just how routine it is.

They were starved and so this 13 and 14 year old girl had to urinate for each other to drink so they would not die

Jane Osagie, International Reproductive Rights Research Group

"Everyone is affected," she says.

"It's either a daughter of a family or a daughter of a friend who has been trafficked."

A rehabilitation centre has been opened in Benin City to offer some alternative to the children.

They are offered sewing, computer or literacy classes. Mismanagement of the Nigerian economy has created dire poverty throughout the country.

The average income has slumped to around $350 a year. The result is that traditional values and family ties are weakened to breaking point and the prospect of making money abroad is proving an irresistible lure.

Voodoo is used to bind girls to their 'sponsors'

Eki Igbenedion, the wife of the governor of Edo State, helped to raise funds for the skills centre after travelling to Italy to see for herself what "work" Nigerian girls are doing there.

"I don't know why it's not getting the attention it deserves because I think that since the slave trade was abolished many years back, it's coming back in a modern form," she says.

The teenagers are recruited by a local agent, a sponsor, who pays for their journey abroad, as well as the bribes and false documents necessary to get them there.

Voodoo is used to coerce the girls into working for their sponsors.

They are then transported on an often fatal journey through a number of West African countries until they reach their departure point where they are sold on to their "madame".

'A lot of them die'

Jane Osagie, co-ordinator of Nigeria's International Reproductive Rights Research Group, has worked with a number of girls who have been trafficked.

"A lot of them die," she says.

"A lot don't come back. There were two girls who were trafficked and because they refused to go into the trade, they were banned from eating."

"They were starved and so these 13 and 14- year-old girls had to urinate for each other to drink so they would not die."

A government campaign aimed at stopping the trade in humans

Because the Italian authorities have become increasingly alert to direct flights from West Africa, the traffickers now use other European countries like Britain and France as staging posts.

Travelers arriving from other European Union states are subject to far less scrutiny and false documents have a greater chance of fooling immigration officers.

Bathed in the orange glow of late-night lights, hundreds of half-naked, high-heeled Nigerian girls and women sell sex.

With debts of up to $50,000, it can take two or three years working night and day to pay off the money.

The physical and psychological debts are enormous. Much responsibility lies with the Nigerian authorities, but Detective Superintendent Dave Gaylor, says the UK and Europe as a whole have a much larger role to play.

Greater police co-operation across borders, harsher sentences for the perpetrators and specific anti-trafficking legislation as well as increased resources would also reduce the exploitation and enslavement of young girls from Nigeria.