World Anti-Doping Agency, WADA has unveiled a new weapon in the fight against drug cheats in London Olympics. WADA Director General David Howman confirmed that for the first time a sophisticated new test for human growth hormone, HGH would be used at the London Games. He said, the new "bio-marker" test was capable of distinguishing between HGH produced naturally in the body and synthetic HGH. Mr Howman said the new test would be used alongside the existing test for HGH, which has been in use since 2004. Mr. Howman's comments come amid the disclousre of the first doping incident in forthcoming Summer games where a Moroccan middle-distance runner Mariem Selsouli tested positive for a banned diuretic.