The report found Russia, China and Indonesia were the main sources, with the EU importing up to 31m cubic metres of wood from illegal origins.
Anke Schulmeister, WWF forest policy officer, said illegal logging pushes wood prices down and results in “major economic losses”.
“Strong measures are needed to protect the world’s remaining forests,” she said.
In Eastern Europe, 23% of wood-based products originated from illegal or suspect sources, compared to 40% in South East Asia, 30% in Latin America and 36-56% in Africa.
WWF is pushing for the introduction of EU legislation to guarantee that only legal wood is traded in the European market.
The European Commission is expected to propose legislation on this issue in the coming months.
WWF suggests EU law to halt increase in logging
The WWF has called for the EU to bring into force strong measures to protect the world's remaining forests after a report found illegal logging is on the increase, with one-fifth of wood being sourced illegally in 2006.
