It is the perfect way for athletes to cheat. No tests - urine, blood or even tissue biopsies - will detect its use. And a leading sports doctor has warned that this new-age development could be in place by the Sydney Olympics. The latest and greatest weapon in the sports cheat's arsenal is gene engineering, which has the potential to create 'super-athletes'', according to a former president of Sports Medicine Australia, Dr Peter Larkins, who described it as the future challenge for everyone in sport.