The European Unions top court has ordered Polands right-wing government to suspend logging in the ancient Bialowieza forest pending a final judgement, a spokesman said Friday.
Bialowieza, straddling Poland's eastern border with Belarus, includes one of the largest surviving parts of the primeval forest that covered the European plain 10,000 years ago.
The UNESCO World Heritage site also boasts unique plant and animal life, including the continent's largest mammal, the European bison.
"We issued a decree yesterday ordering the immediate halt to the forest's exploitation," an EU Court of Justice spokesman told AFP on Friday.
He added the order was "temporary" pending a final court ruling in the case, which could take months, possibly years.
The court was acting on a July 13 request by the European Commission, the 28-nation EU executive, for "interim measures" to stop large-scale logging in "one of Europe's last remaining primevel forests."
The Polish government has said it authorised the logging, which began in May last year, to contain damage caused by a spruce bark beetle infestation and to fight the risk of forest fires.
But scientists, ecologists and the European Union have protested and activists allege the logging is a cover for commercial cutting of protected old-growth forests.