A maize shipment to the Netherlands that Greenpeace said contained illegal genetically modified grain must be returned to the United States if testing confirmed this, the European Union said on Monday. A European Commission spokesman said the European Food Safety Authority had found that the type of genetically engineered maize Greenpeace said was in the shipment was not a health threat, but it had yet to be approved for use in the EU. ”It is still unlawful at the moment,” Michael Mann said.