BERLIN, Germany -- FIFA's chief medical official expects the World Cup to be drug free.

Soccer's governing body conducted more than 125 tests in 24 international friendlies and all 32 training camps before the tournament started last Friday, and tested two players from each team in the opening matches.

So far there have been no positives, Dr. Jiri Dvorak said Sunday, confirming that some of the sport's biggest stars had been tested.

Dvorak demonstrated FIFA's doping test procedures in detail at a news conference, saying he wanted to show the system was thorough.

"We want to prove there's no problem with doping or testing in football," he said. "I get sick of being criticized for something I think we do much better than most" other sports.

Soccer last week became the last of 28 Olympic sports to sign up to the World Anti-Doping Agency's code, ending months of debate over whether FIFA should agree to the globally recognized minimum two-year ban for first offenses.

FIFA's congress accepted the WADA guidelines, with the proviso it could sanction on a case-by-case basis.

Dvorak said there was "not a great magnitude" of performance-enhancing drugs in soccer, with the bulk of positives for recreational drugs.

He said there was a 15 percent increase in testing between 2004 and 2005 and a decrease in the number of positive cases.

In 2004, FIFA conducted 20,750 doping tests and had 88 positive cases, including 13 for performance-enhancing substances. Last year, 23,478 tests turned up 78 positive cases, including nine for performance-enhancing substances like anabolic steroids.

"We're the world leader in terms of the tests we carry out," Dvorak said. "The big teams and the star players are right behind (the testing) -- I don't think we'll see any problems at the World Cup."