A lawsuit alleging Nestle, Cargill and Archer Daniels Midland “aided and abetted” child slavery in Cote d’Ivoire can proceed after an intervention by an appeals court in the US.

The US Court of Appeals for the Ninth Circuit said three plaintiffs said to have been child slaves in the African state will be allowed to amend and re-introduce a 2005 lawsuit that had been thrown out in 2010.

The unnamed complainants claim they were forced to work on cocoa plantations for up to 14 hours a day for six days a week. They allege they were locked in small rooms at night and not permitted to leave the plantations, knowing that children who tried to escape would be beaten or tortured. One plaintiff claims to have witnessed guards cut open the feet of children who attempted to escape. Another claims guards forced failed escapees to drink urine.

Nestle, Cargill and ADM are alleged to have “aided and abetted child slavery by providing assistance to Ivorian farmers”, the court said.

“Reading the allegations in the light most favorable to the plaintiffs, one is led to the inference that the defendants placed increased revenues before basic human welfare and intended to pursue all options available to reduce their cost for purchasing cocoa. Driven by the goal to reduce costs in any way possible, the defendants allegedly supported the use of child slavery, the cheapest form of labour available,” senior circuit judge Dorothy Nelson wrote.

Speaking to just-food, Nestle said: “We continue to believe that the trial court was correct in its 2010 dismissal of this case. The appellate court’s decision relates to purely procedural issues and is not determinative of the allegations against Nestlé, which remain unproven.”

It added: “Nestle follows and respects international law and it does not tolerate illegal or discriminatory labour practices.”

Cocoa supplier Cargill said it was “disappointed” in the latest ruling but insisted: “We believe this to be a temporary setback and are confident that we will ultimately prevail in this suit.”

The agribusiness group added: “Cargill is concerned about the safety and well-being of children who may be involved in dangerous or forced work on cocoa farms, and we are committed to working towards a cocoa supply chain where no children are subject to these conditions.”

Archer Daniels Midland said it disagreed with the court’s decision. “We are examining the decision and anticipate that the defendants will file an en banc petition with the full Ninth Circuit,” it added.

[This article was updated at 15:56 BST on Tuesday 9 September to include ADM’s statement].