The Beijing Games could provide a record haul of drug cheats because more testing will be done and the tests themselves are better, World Anti-Doping Agency chief John Fahey said Thursday.
The WADA boss said 4,500 samples would be scrutinized - a quarter more than in Athens four years ago - and that there was pressure from within sport for athletes to be drug-free, reported dpa.
"I believe there's a far greater awareness within individual teams of the need to be clean," he told Australia's ABC Radio. "I also believe that the resources on the ground that China are providing is quite impressive."
There were 24 drug busts at the Athens Olympics.
Fahey also said gene doping was the next frontier for athletes seeking an unfair advantage through clinical enhancement of their performance.
In gene doping, athletes put a second copy of certain cells into their bodies to try to increase muscle mass or improve endurance.
"It's highly dangerous," Fahey said. "It has the potential not just to cause serious illness, such as leukemia, but also death."
"We believe we're close to a breakthrough in detecting it, but I guess the message on gene doping is to say to any athlete who is even contemplating it, your life is not worth it - and that what could be at risk if you wish to participate in it."