The online sale of endangered and threatened wildlife is rife across Europe, a new investigation has revealed, ranging from live cheetahs, orangutans and bears to ivory, polar bear skins and many live reptiles and birds.

Researchers from the International Fund for Animal Welfare (Ifaw) spent six weeks tracking adverts on 100 online marketplaces in four countries, the UK, Germany, France and Russia. They found more than 5,000 adverts offering to sell almost 12,000 items, worth $4m (£3m) in total. All the specimens were species in which trade is restricted or banned by the global Convention on the International Trade in Endangered Species.

Wildlife groups have worked with online marketplaces including eBay, Gumtree and Preloved to cut the trade and the results of the survey are an improvement compared to a previous Ifaw report in 2014. In March, 21 technology giants including Google, eBay, Etsy, Facebook and Instagram became part of the Global Coalition to End Wildlife Trafficking Online, and committed to bring the online illegal trade in threatened species down by 80% by 2020.

“It is great to see we are making really significant inroads into disrupting and dismantling the trade,” said Tania McCrea-Steele at Ifaw. “But the scale of the trade is still enormous.”

Almost 20% of the adverts were for ivory and while the number had dropped significantly in the UK and France, a surge was seen in Germany, where traders developed new code words to mask their sales. “It is a war of attrition and we can never let our guard down,” said McCrea-Steele. The UK is implementing a stricter ban on ivory sales and the EU is under pressure from African nations to follow suit.