SYDNEY (AFP) - Australia holds the largest claim to Antarctica but risks losing it in any race to unlock the frozen continent's potentially vast mineral and energy resources, an influential thinktank said Monday. The Lowy Institute has warned Canberra against complacency when it comes to its claim, which covers 42 percent of Antarctica, an area roughly three-quarters the size of Australia. "Australia has limited Antarctic presence and capability, and positions its policy in terms of science and environmental management rather than national security," Lowy's national security fellow Ellie Fogarty said .