Child slavery is endemic in the chocolate industry, Geoff White, the New Zealand general manager for Trade Aid, says.

The recent addition of palm oil to Cadbury's chocolate and the implied threat this poses to rainforests and the Indonesian orang-utan has raised a large amount of media attention and consumer backlash.

As it should.

But while concern for the environment and animals is justified, it is unfortunate that a far bigger scandal involving much of the chocolate sold in this country continues to fly under the radar.

Slavery, and especially child slavery, is endemic within the chocolate industry.

More than 40% of the world's supply of cocoa is sourced from the Ivory Coast where, it is claimed, some 90% of cocoa plantations use slave labour.

In 2003, the US State Department estimated there were more than 109,000 children in forced labour on cocoa farms in the Ivory Coast.

How did this come about? Child slavery on cocoa farms in the Ivory Coast began to become prevalent after cocoa prices fell during the 1980s and '90s.

Before then, cocoa farmers were protected by a government-supported price system, but this was dismantled in a structural adjustment programme enforced by the International Monetary Fund as a condition of World Bank loans.

As farmers' incomes dropped, living standards declined markedly and, in an effort to cut production costs, the use of child labour became widespread.

Continuing low prices led eventually to the use of child slaves, most of whom are trafficked across the border from neighbouring Mali.

Initial efforts to eliminate this practice, carried out by the International Labour Organisation (ILO) with the help of nine West Africa governments, were well-meaning but ineffectual.

In October 1999, the ILO launched an initiative ("Combating Trafficking in Children for Labour Exploitation in West and Central Africa") with support from the US Department of Labour.

Then the Ivory Coast and Mali signed a bilateral co-operation agreement to fight cross-border child trafficking in 2000.

Neither of these efforts was able to stop the steady increase in the use of child slaves on cocoa farms.

In 2001, media in the United States exposed the involvement of child slaves in the supply chains of US chocolate companies.

The resulting negative publicity was huge as consumers began demanding that action be taken to ensure their chocolate treats were not responsible for assigning African children to years of servitude, ill-health, lack of family support and missed opportunities for education.

US Senator Tom Harkin and Representative Eliot Engel took up the issue and introduced a Bill that would require chocolate manufacturers to label their product slave free if they wanted to sell it in the US.

While the Bill was passed by the House of Representatives, furious lobbying by the industry saw it stymied in the Senate.

A compromise was reached and the Harkin-Engel Protocol was established.

This was a watered down agreement whereby the chocolate industry agreed to voluntary standards to solve the "child labour" problem (reference to slavery was removed from the original Bill) by July 2005.

Instead of focusing on its own culpability for creating the conditions that reward farms for using child slaves (conditions such as dropping the price paid to cocoa farmers), the industry attempted to use the protocol to shift responsibility for reform from its own shoulders to those of national governments and the ILO.

What was initially devised as a commitment by the cocoa industry to develop and implement certification of its cocoa supply was deemed to be the responsibility of the Ivory Coast Government, even though it was obvious to everyone the Government did not have the resources to do this.

The industry-proposed system did not even attempt to identify farms that used illegal child labour (slaves), focusing instead on measuring any improvements in labour conditions on a country-wide basis.

Despite this blatant shirking of responsibility, the chocolate industry failed to meet its 2005 deadline.

It was given another three years, to July 2008, by which time it had still failed to meet the targets.

The industry tried to defend itself by claiming that its obligations were being met by the establishment of pilot projects in Ghana and the Ivory Coast designed to test a new labour-monitoring programme.

So, while no effort was made to combat the problem, a programme to see if they could measure the problem was deemed sufficient by these multibillion-dollar corporations.

In other words, it was business as usual for the chocolate companies and the child slaves who worked for them.

This lack of moral and social obligation was highlighted in a response to a lawsuit filed by the International Labour Rights Fund in 2005 against Nestlé, Archer Daniels Midland (ADM) and Cargill (both suppliers of cocoa to Mars/M&M and Hershey) on behalf of Malian children trafficked to the Ivory Coast to work in the cocoa plantations.

Challenged on some of the assertions made by the companies in their corporate social responsibility statements, the lawyers argued that the codes of conduct were simply "aspirational".

They stated that it "simply is not reasonable to construe policy statements as, for example, imposing an enforceable contractual obligation on Nestlé to monitor its suppliers' treatment of children or on ADM to affirmatively act if it knew that its suppliers used child labour".

In New Zealand, many of our chocolate companies source their cocoa beans from Ghana.

When questioned, they simply say that Ghana does not have a child slave problem.

This may well have been the case a few years ago but, faced with unfair competition in the form of lower prices from neighbouring Ivory Coast, cocoa farmers in Ghana are beginning to use child labour and look set to follow the downward spiral into the use of child slaves.

Already, it is no longer possible to say that purchasing from Ghana ensures no child slaves are involved in the supply chain.

New Zealand chocolate companies all have codes of conduct and corporate social responsibility statements that testify to their moral standing but, if they do not know where and from whom they source their cocoa, these words are as meaningless as those of the US companies have proved to be.

That a product such as chocolate, a favourite of children everywhere, is reliant on child slavery to produce profits is a sorry indictment on all those involved.

Yet the biggest impetus for change is in the hands of the consumer.

August 23 is the International Day for the Remembrance of the Slave Trade and its Abolition.

It would be appropriate for all chocolate manufacturers to declare their product slave-free on this date.

I would urge all consumers not to buy from any manufacturer who cannot answer the question, "Is your product slave free?" with a simple "Yes".