The move was met with relief by scientists who heaped scorn on the French study after it was published last year. The study claimed a steady diet of genetically modified corn caused tumours in rats.

But observers say the damage will be hard to undo.

The retraction is “good news,” says biologist Robert Wager, at Vancouver Island University, who objected to the study from the outset. But he says “it’s worrisome it took over a year for the journal to do the right thing.”

He predicts Gilles-Eric Seralini, of the University of Caen who led the study, will now be viewed as a martyr by believers in the dangers of GM crops and food. “The power of pseudo-science to generate fear must not be underestimated,” said Wager. “Once instilled, facts rarely dissipate that fear.”