The New Zealander at the head of the World Anti-Doping Agency David Howman, says they're determined to crack down on any Olympic drug-taking athletes.
Even before the opening ceremony in London, the International Athletics Federation has revealed that nine track and field athletes have been handed lengthy bans for doping violations in the leadup to the Games.
They include two leading Moroccans, the women's 1500 metres favourite Mariem Selsouli who had already served a two year suspension for doping, and now faces a lifetime ban, and the leading mens marathon runner Abderrahim Goumri.
All the athletes were caught with the aid of the Athlete Biological Passport programme, which is being used for the first time in London.
The director-general of the World Anti-Doping Agency, David Howman, says the challenge is always to keep ahead of drug-taking athletes who seek new methods to beat drug tests.