British shoppers could be unknowingly buying wooden furniture, flooring and even food items that are byproducts of destructive illegal logging in the Amazon, environmental campaigners are warning.

Friends of the Earth is calling on ministers to make companies reveal the source of their products in order to stop the black market trade. Last week human rights watchdog Global Witness revealed that 185 environmental activists were killed in 2015, many of whom had been trying to stop illegal logging in the Amazon. An estimated 80% of Brazilian hardwood is illegally logged.

Vast areas of forest in Brazil, the Philippines and Colombia are cut down by criminal gangs. Multinational companies then use the land for palm-oil production, mining or cattle-grazing, while the wood is sold off, according to Patrick Alley, co-founder of Global Witness.

Local activists – often villagers or indigenous people – are at the forefront of campaigns against these activities, but they are attacked and harassed by security forces and the gangs, Alley said. The worst-hit country was Brazil where 50 activists were killed last year, mostly in Amazonia; 33 died in the Philippines and 26 in Colombia.

Friends of the Earth campaigner Alison Dilworth said companies and governments often did not acknowledge that local communities had any rights to their land.

“The outrages committed against environmental activists in many parts of the world shows how threatened the environment is from large-scale deforestation and illegal logging,” she said. “It’s time governments pressed for more supply-chain transparency so we can identify which companies and what products on supermarket shelves are directly implicated with deforestation and human rights abuses.”

It is almost impossible to tell whether rare tropical hardwoods were logged legitimately or not Richard George, Forests for Greenpeace UK

Yet it is very difficult for consumers to establish whether or not a product contains palm oil from looking at the packaging.

“What’s lacking here is due diligence by companies on their supply chains,” Alley said. “It’s too easy for companies not to ask questions about the land they are using. They should include due diligence on what happens to local people in the area where they operate.”

Richard George, Head of Forests for Greenpeace UK, said it remained almost impossible for consumers to tell whether hardwood had been obtained legitimately.

“There has been a strong link between commodities like palm oil and tropical timber, land-grabbing and the murder of environmental activists,” he said.

“But it’s in South America where illegal loggers are waging the most intensive war on indigenous peoples and local communities. Much of that illegal timber is logged for export to Europe, and it is almost impossible to tell whether rare tropical hardwoods like Ipe were logged legitimately or not. If, as either a concerned consumer or a responsible timber importer, you have even the slightest doubt about the provenance of a South American hardwood product, walk away.”

Britain adopted EU regulations in 2013, with the Timber and Timber Products (Placing on the Market) Regulations preventing illegally logged Brazilian mahogany, teak and other hardwood from being used in the UK. In the last two years, 132 investigations have been conducted by the Department for Business, Innovation and Skills, although no company has been fined.

Anyone importing timber or using imported timber has to keep detailed records of the source of the wood. David Hopkins, the managing director of the Timber Trade Federation (TTF), said that responsible timber importers and companies that use Brazilian hardwood in their products had to follow a strict audit process.

“Palm oil is a high-value cash crop,” he said. “You can harvest the oil on a regular basis, whereas trees take 40 years to grow. It’s in mayonnaise, shampoo, every consumer foodstuff you’re likely to buy. People clear tracts of forest and replant them quickly but they have to do it fast, and when people stand up to them, that’s when violence occurs.

“The forestry industries get tagged with this, and there is a danger that they enter the supply chain, but if your livelihood depends on timber, you chop down fewer trees and use them in a more efficient manner and keep trees standing.”

Kitchen work surfaces, decking, flooring and window frames should all be marked with an FSC logo, showing that it meets standards approved by the Forest Stewardship Council, Hopkins said.

The TTF is introducing technology that will allow suppliers to test hardwood to establish its species and validate claims from suppliers in Brazil and elsewhere.