The world's biggest food company, Nestle SA, says it will work with a non-profit group to investigate child labour on cocoa farms in Ivory Coast that supply its factories.

Little has changed in the decade since the Swiss company and other major chocolate makers signed a U.S.-brokered international agreement in September 2001 to rid their supply chains of child labourers.

Now, Nestle says it is joining the Fair Labour Association (FLA), a group that evolved out of a U.S. presidential task force in the Clinton White House, to probe cocoa fields that supply its products, checking for abuses.

FLA says its audit will be independent, with unannounced visits to a sampling of farms.

The results will be made public in spring 2012. The firm said the FLA would send a team of independent examiners to Ivory Coast — where Nestle buys most of its cocoa — to map the supply chain. The U.S. government-backed report by Tulane University, published in March, found that more than 1.8 million children in West Africa were involved in growing cocoa.

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