Olympic officials are confident of catching drugs cheats at the Vancouver Games with an anti-doping programme they say is more extensive than ever before, dpa reported.
Vancouver's doping laboratory has already tested more than 300 blood and urine samples from Olympic athletes, it was revelead Tuesday.
More than 800 athletes will be tested before their competition and some 2,000 doping controls are expected during the Games.
There have been no positive tests so far.
International Olympic Committee medical commission chairman Arne Ljundqvist said he was confident drugs cheats would be exposed - if not during the Games than later.
"I am sure that we are getting the Games cleaner and cleaner for every edition," he said.
The vast majority of the some 2,500 athletes at the Olympics will be tested at least once before the Games end on February 28.
The testing began with the opening of the Olympic village on February 4 and all athletes - even those still at training camps abroad - have to be available for testing.
Christiane Ayotte, the scientist in charge of the laboratory at the Richmond Oval, told reporters the laboratory would be working around the clock during the Games and was equipped to proviode testing "of the highest quality possible."
She added: "We can test all prohibited substances for which there is an existing method. We have incorporated all the latest potential drugs and medication we know could be taken by athletes so we are pretty confident we have done the best that could be done."