Monsanto Co.'s genetically modified NK603 corn is hazardous to the health and should be banned, according to South Africa's African Centre for Biosafety.

The centre has asked South African authorities to ban the corn's cultivation, import and export based on a French study that claims the corn can cause tumors, liver damage and kidney damage in laboratory rats. “We urge the South African government to take the necessary steps to protect its citizens,” said the centre in a letter to the minister of agriculture, forestry and fisheries.

But the study “does not meet minimum acceptable standards for this type of scientific research,” said Thomas Helscher, a spokesman for Monsanto. The methods used don’t conform to Organization for Economic Co-Operation and Development standards, the source and quality of the corn are unclear and details on dietary intake absent, he said.

France has asked its national food-security agency to look into the study, and Russia's government has suspended sales of NK603 corn pending further information.