BRUSSELS (AFP) - NATO said it lost radar contact with a drone helicopter conducting a reconnaissance flight over Libya on Tuesday, denying one of its attack helicopters had crashed. The alliance's command centre in Naples, Italy, lost track of the unmanned autonomous helicopter drone at 0720 GMT, NATO military spokesman Mike Bracken said in a statement. "This drone helicopter was performing intelligence surveillance and reconnaissance over Libya to monitor pro-Kadhafi forces threatening the civilian population," he said. The military alliance was looking into the reason behind the incident.