Cheating is still rife in sport despite improved testing and more than half the sprint semifinalists at the London 2012 Olympics are likely to use illegal drugs at some stage of their preparations, says Victor Conte, the man at the heart of the BALCO doping scandal. “Do I think it's still rampant cheating in sports? Yes, I do,” the American told Reuters in an interview ahead of the 10th anniversary of the World Anti-Doping Agency (WADA) next week. Asked how many of those who reach the 100 meters semifinals at the London Games could have used performance-enhancing substances in his opinion, Conte said: “I will use the term ‘overwhelming majority'. “I will not say at the competition there were drugs in their system while competing. But during the previous year, at some point during their preparation for this final, with the top-16 two semifinal races, I still believe the majority of athletes will have used some sort of prohibited substance or method.” Conte's tiny laboratory on the outskirts of San Francisco became ground zero of a huge steroid scandal in 2003 that continues to reverberate around the sporting world, destroying careers – including his own. A former bass guitarist who turned a gregarious personality and self-taught knowledge of nutrition into a doping empire, Conte spent four months in prison after being convicted of distributing steroids. He said drug testing had improved but loopholes remained that someone could “drive a Mack truck through”. “It's a cat-and-mouse game and maybe I am the self-proclaimed greatest mouse who ever lived,” said Conte, speaking with the clinical authority of a pharmacist reeling off scientific facts and studies at a rapid pace. “But I know how the mice think. That is what I did for a number of years – find out where the loopholes were and how to circumvent and defeat their policies and procedures. “I was able to do it successfully for a number of years. I think that ironically qualifies me to make a contribution.” Conte's client list featured some of sport's biggest names, including disgraced sprinters Marion Jones and Tim Montgomery who powered their way to Olympic medals and world records with the help of BALCO performance-enhancing products. Drug cheats continued to hold the advantage in almost every sport, including Olympic events, despite the efforts of the WADA, Conte said. “Is it still easy to circumvent the anti-doping policies and procedures in place today not only in professional sport but Olympic sport WADA regulates,” said Conte, adding that the WADA and the United States Anti-Doping Agency (USADA) had wasted millions of dollars testing athletes who knew they were going to be targeted. “What you're doing now is not effective. They need to take those dollars and travel to the home soil of the many countries that do not have independent anti-doping federations and test these athletes during the off-season. “Testing athletes at competition is more of an IQ test than a drug test because athletes have to be pretty stupid to fail a drug test at a competition. “You want to use steroids during the off season because that is when you build your explosive strength base and believe me it serves you months and months later during the competitive season. “You need to increase the number of tests in the fourth quarter, this is when the athletes use the drugs. But instead of increasing the number of tests in the fourth quarter, as I advised, they cut them in half. “They are enabling, harboring and promoting the use of drugs or they are ignorant. “Why, when this is the time you have been advised the fish are biting, (do) you lean your pole up against the tree, put a straw hat on and take a nap?”