David Howman, director-general of the World Anti-Doping Agency, on Stephen Swart's contribution to unmasking cycling's drug cheats:
"In the fight against doping in sport, it has become increasingly obvious that science alone does not detect all those who are cheating. One only needs to look at the career of Marion Jones, where she tested more than 160 times and none of them returned a positive result. The same can now be said for Lance Armstrong.
"Accordingly, those engaged in anti-doping programmes are relying more and more on evidence gathered in other ways. Whether it be evidence collected by the police, or customs, or individuals who volunteer evidence all can be used to ensure those sophisticated cheats such as Armstrong do not prosper. WADA encourages those who have such information to come forward.
"We, however, fully recognise the risk that such individuals take. The code of silence, omerta, has prevailed in the world of cycling for many years and to step outside of it has meant banishment from the sport totally. This zero tolerance approach will never lead to a cleaning up of that sport. Riders must be encouraged to come forward and must not feel threatened if they do so.
"Looking back now, I can fully comprehend the risk that Steve Swart took when he opened up about Lance Armstrong many years ago.