A survey released on Thursday details the true extent of child labour in the cocoa sector of West Africa.

Dr Rodomiro Ortiz at the International Institute of Tropical Agriculture (IITA) in Nigeria, told the BBC's World Business Report that 254,000 children had been identified as working in hazardous conditions.

He said, however, that the number was not as high as previously assumed and that child labour in that sector was not an exception.

"When you go through different cities, not only here in Africa but throughout the developing world, you'll find that child labour is not an exception," he said.

Tradition or slavery?

The IITA, which conducted the survey in association with other agencies such as the International Labor Organisation (ILO) and the US Agency for International Development, had to decide what constituted family tradition and what could be labelled child labour.

West Africa supplies almost 70% of the world's cocoa

43% Ivory Coast 15% Ghana 7% Nigeria 4% Cameroon

"We used the international definition derived from ILO convention 138, which states that child labour is any economic activity performed by a person under 15."

The greatest hazards facing children are using pesticides without protective clothing and the use of machetes to clear land.

Human traffic

The survey gives a better insight into the exact numbers of children involved, and the nature of their dangerous working conditions.

Children working with their family can be an acceptable socialising activity.

Ben Foot, Save The Children Fund

The main concern is that these children receive no education, and are therefore trapped because they cannot find other work to lift them out of poverty.

The organisations behind the survey want a co-ordinated approach to governments to address the issue.

'Socialising activity'

But Ben Foot at Save The Children Fund in Nigeria told BBC News Online that the main thing which had to be addressed by governments was the trafficking of children.

"Children working with their family can be an acceptable socialising activity."

"But problems arise when they are brought from very poor families and paid a pittance on the plantations," he said.

He added that those children receive no education and rarely return home.

"Once plantations have no further use of a child, who by then had lost all contact with their families, they tend to hit the streets as delinquents."