Sinewy, silvery trees rise from the green landscape of Marahoué national park, their smooth trunks supporting branches only at the very top. Marahoué is one of eight national parks in Ivory Coast and 20 years ago it was covered by forest and home to chimpanzees and elephant herds.

Now it is more common to see the skeleton of a tree, slowly burnt by fire to get rid of the shadow it casts over cocoa fields, or just a sawn-off stump.



Henri, a traditional leader from the nearby town of Diafla, grew up with the forest, and speaks lovingly of its towering iroko trees – but he had a hand in destroying it. Like many others, he has cocoa plantations inside the park and employs people from Burkina Faso to work on them.



“This all used to be trees, but farmers burned them to plant cocoa,” Henri says. When he was younger, he used to see chimpanzees and elephants make their way through the park. They have been replaced by people.

Having run out of petrol on his way into Marahoué, Henri leaves his motorbike by the track and makes the rest of his journey on foot, passing herds of cattle, the ubiquitous scrappy cocoa plants, and the remains of a tourist lodge that was destroyed in 2008, shortly before the village of Zanbarmakro was founded nearby.

The remains of a burnt tree in Mont Tia forest reserve, Ivory Coast. Photograph: Ruth Maclean/The Guardian

Nobody uses the word “village” for Zanbarmakro, preferring the more temporary-sounding “camp”. But the large new church being built at one end, the mosque at the other, as well as the homes, shops and private clinic in between dispel any pretence that this place, home to 13,000 people, is not here to stay.



Mid-afternoon, men arrive on their motorbikes from the plantations and rest on the stoop of a shop selling fizzy drinks. Women spread out their wares: one, a higgledy-piggledy pile of shoes, another, a rack of scythes, the sort every child carries for harvesting. Cassava mills whirr. By some estimates there are 50 illegal villages inside the park. Zanbarmakro is one of the biggest.



Nestled at its entrance is a lookout post on stilts built years ago by the OIPR (Office Ivoirien des Parcs et Réserves), the state parks authority. Its rangers have the job of ensuring that no trees are cut down, no wild animals hunted, and certainly no villages built in the park. Strangely, they seem not to have spotted the bricks and cement for the church and mosque arrive, nor the trucks loaded with cocoa beans or timber leave.



Henri introduces Zoughory Laji Bourema, Zanbarmakro’s chief, who steps round a large white tarpaulin spread with drying cocoa on to his verandah. “I get a bit of trouble from the OIPR,” he admits, smoothing down his shiny purple boubou.

Q&A How does 'dirty' cocoa end up in our chocolate? Show The chocolate industry works mainly as follows: small-scale farmers grow cocoa on plantations, many of which are illegal as they are in national parks or protected forests. They sell it to middlemen with motorbikes known as ‘pisteurs’, or direct to buyers in local towns. These supply traders, which are often multimillion-dollar companies, which in turn sell to big chocolatiers. There are so many transactions in the supply chains that big brands sourcing from implicated traders cannot be sure their product is not contaminated.

The OIPR’s rangers spend much of their time drinking tea and checking WhatsApp at the residence behind their office, a few miles from the park’s boundary. Occasionally, though, they leave their camp beds to go “hunting”. They descend on a plantation, arrest a few farmers every week, and lock them up until the community pays for their release. The ransom is well known: 100,000 francs per person (£140), or 150,000 francs if they are caught with a motorbike.



“They come into the villages, collect money – a few million francs a time – and then go again,” says Henri, searching in vain for some tree shade of a tree to protect himself from the sun. “They come [for it] in their four-wheel drives about twice a month.”

In May, locals say the bribe they handed over was the biggest ever – the equivalent of £13,000, paid to the local OIPR chief. (A request for comment from the OIPR’s chief, Colonel Tondossama Adama, did not elicit a response.)



In return, they can stay and farm cocoa, which they sell to the agents of buyers in the nearby cities of Bouaflé and Bonon, who in turn sell it to Saco, a subsidiary of Barry Callebaut, which in turn supplies a string of global chocolate brands.

When approached for comment, Barry Callebaut did not deny the specific allegation that illegal deforestation cocoa had entered its supply chains and said: “There is cocoa farming happening in high conservation value areas in West Africa.” Barry Callebaut restated a commitment to be totally deforestation-free by 2025.

The Guardian travelled through Ivory Coast with the Mighty Earth group to investigate the impact of cocoa on the dwindling rainforest. We both interviewed traders and managers of cooperatives who said they bought cocoa from protected areas and sold to Olam, a global agri-business. Olam acknowledged one incident it said was isolated and added that it was pursuing a string of initiatives to assure a clean supply chain.

“Olam is absolutely clear that deforestation by cocoa smallholders must be halted,” a spokesperson said, while adding nonetheless: “it is a complex and highly fragmented supply chain so the challenges of tracing back to each individual farmer are immense”.

Despite Prince Charles’s success in extracting promises from industry that they would come up with a plan to reverse deforestation, the message has not got through to cocoa producers and traders on the ground.



Farmers arrive with cocoa beans at a trader’s in Taobly, Ivory Coast. The beans will eventually make their way to big chocolate companies. Photograph: Ruth Maclean/The Guardian

At one cocoa yard belonging to a buyer called Sivacco in the city of Man, men sift the beans through big metal rectangular sieves and shovel it into sacks, one wearing a Father Christmas hat. Opposite the yard is a sprawling sawmill with piles of sawdust, planks and logs, and smoke billowing out behind it.

“We definitely have cocoa from the forest reserves here,” says the yard manager, who did not want to be named. “Pisteurs (motorcyclists) bring it here and we can’t tell where exactly it comes from. We sell to all the big companies.”

Behind him is a big mural with the Rainforest Alliance symbol and a list of forbidden activities.

“We don’t care. We don’t even ask the producers where it comes from. The big companies never ask where it comes from either,” says Bamogo Arouna, a buyer in Taobly, a town on the edge of Mount Tia, a classified forest in the west of Ivory Coast. Arouna says he sells to two big exporters who sell cocoa products to companies including Nestlé, Mars and Hershey.



Farmers ride their cocoa-laden bicycles from the reserve to Arouna’s warehouse which emits the sickly raw cocoa smell that, strangely, smells nothing like chocolate. One farmer unloads a half-full sack of cocoa from his bike rack and men begin to toss it through giant sieves.



“Cocoa is cocoa,” shrugs a trader, looking over the lush landscape in front of him. “We just pay whoever has it. We don’t differentiate between forest reserves or non-forest reserves.” When he came to the area from Burkina Faso 12 years ago the view was of tropical forest; now, it’s crops. To him, it makes no difference.



“It was green when I arrived,” he says. “It’s still green.”