A US military agency is investing $100m in genetic extinction technologies that could wipe out malarial mosquitoes, invasive rodents or other species, emails released under freedom of information rules show.

The documents suggest that the US's secretive Defense Advanced Research Projects Agency (Darpa) has become the world's largest funder of "gene drive" research and will raise tensions ahead of a UN expert committee meeting in Montreal beginning on Tuesday.

The UN Convention on Biological Diversity (CBD) is debating whether to impose a moratorium on the gene research next year and several southern countries fear a possible military application.

UN diplomats confirmed that the new email release would worsen the "bad name" of gene drives in some circles. "Many countries [will] have concerns when this technology comes from Darpa, a US military science agency," one said.