An anonymous reader writes: Three science papers that had suggested that genetically modified crops were harmful to animals and have been used by activist groups to argue for their ban have been found to contain manipulated and possibly falsified data. Nature reports: "Papers that describe harmful effects to animals fed genetically modified (GM) crops are under scrutiny for alleged data manipulation. The leaked findings of an ongoing investigation at the University of Naples in Italy suggest that images in the papers may have been intentionally altered. The leader of the lab that carried out the work there says that there is no substance to this claim. The papers' findings run counter to those of numerous safety tests carried out by food and drug agencies around the world, which indicate that there are no dangers associated with eating GM food. But the work has been widely cited on anti-GM websites — and results of the experiments that the papers describe were referenced in an Italian Senate hearing last July on whether the country should allow cultivation of safety-approved GM crops. 'The case is very important also because these papers have been used politically in the debate on GM crops,' says Italian senator Elena Cattaneo, a neuroscientist at the University of Milan whose concerns about the work triggered the investigation.