PARIS (Reuters) - Bayer said on Wednesday that farmers in France and Germany were digging up thousands of hectares of rapeseed fields after traces of genetically modified organisms (GMOs) banned for cultivation were found in seeds sold by the company.

GMO crops are widely grown across the world, but they remain controversial in Europe, where very few varieties are authorized for growing and some countries like France have completely outlawed their cultivation, citing environmental risks.

Checks by the French authorities during the autumn showed minute quantities of GMO seeds, estimated at less than 0.005 percent of the volume, in three batches of rapeseed seeds sold under the Dekalb brand, Catherine Lamboley, Bayer’s chief operating officer for France, said.

Dekalb was previously a Monsanto brand before the U.S. company was taken over by Bayer last year.