BEIJING — As Jamaican sprinter Usain Bolt smashed three world records in jaw-dropping form these Olympics, everyone from athletes to journalists has been asking the same questions.
Was the seemingly superhuman Bolt the real thing or the product of state-of-the-art chemistry? Even if he passed his doping tests, what tricks did he use?
The cynicism reflects the shadowy underside of the Games, where superstar runners turn into maligned cheaters overnight after failing drug tests and astounding feats inspire suspicions that performance-enhancing drugs were involved.
So far, this Olympics has not been marked by the kind of doping scandals that plagued past games, and the number of athletes caught during competition using drugs promises to be the lowest in 12 years. Bolt so far has passed an array of rigorous drug tests.
Whether that good news can put to rest public suspicions, however, remains to be seen.
"It's unfortunate what has happened to the sport and it has to be addressed and it is being addressed," said U.S. sprinter Michael Johnson, whose world record in the 200-meter dash was broken Wednesday by Bolt. "But if someone wants to believe the only way (Bolt) can do what he's doing is through doping, that is their prerogative."
By the end of Saturday, six of the nearly 11,000 athletes taking part in the Beijing Games had been caught violating International Olympic Committee doping rules while in competition. None of them was Americans.
That's lower than the 26 violations caught in Athens four years ago but higher than the two in-competition violations of the 1996 Atlanta Games.
Clearing the Games' reputation had been a top priority for the IOC coming into Beijing, and the number of doping tests conducted in competition jumped from 3,500 in Athens to a total of 4,500 planned by the end of the Beijing Games, IOC officials said.
The IOC also launched its first coordinated pre-games testing program, which caught 39 athletes and barred them from participating before the Aug. 8 opening ceremony. Such tests, for example, led to the entire Bulgarian weightlifting team to drop out before the Olympics.
While more positive drug test results could still turn up, especially for substances such as the blood booster erythropoietin, or EPOs, that take longer to detect, IOC officials were celebrating what they said was a victory for athletic fair play.
"We feel the deterrent effect played a part in what we see," said IOC spokeswoman Giselle Davies. "The athletes know that at this event the IOC, which is the organization running the doping programs, means business in not having those who cheat as a part of these events."
Catching dopers is a kind of pharmaceutical race where regulators try to discover the latest strain of steroids, hormones and other chemicals that can help athletes get faster and stronger, while laboratories serving athletes find new drugs that can avoid detection or invent masking agents to throw off the latest tests.
In many cases, laboratories are winning the race. U.S. sprinter Marion Jones, for example, managed to beat the tests while using the steroid tetrahydrogestrinone, or THG, to win five medals in the 2000 Sydney Olympics.
She was caught in 2007 during a federal investigation into a Bay Area laboratory that had supplied cutting-edge performance-enhancing drugs to many high-profile athletes. Jones was stripped of her five medals and is serving a six-month prison sentence after pleading guilty to lying to federal agents.
Jones' downfall was only the latest in several scandals involving sprinters. In 1988, superstar Canadian runner Ben Johnson was stripped of his gold medal in the 100-meter dash after testing positive for steroids.
Anti-doping testers, however, are catching up to the laboratories, especially as unannounced tests and other methods enter the mix, said David Howman, director general of the Montreal-based World Anti-Doping Agency, which administers the IOC tests.
"Athletes would be stupid in the extreme to go into competition full of dope," Howman said. "If you have juice on board, you'll bring shame on your country, your family, your country and your sport."
The six athletes who have failed doping tests in Beijing so far are Ukrainian weightlifter Igor Razoronov, Ukrainian heptathlete Lyudmila Blonska, Greek hurdler Fani Halkia, North Korean shooter Kim Jong Su, Spanish cyclist Isabel Moreno and Vietnamese gymnast Thi Ngan Thuong Do.
Kim was stripped of silver and bronze medals, while Blonska lost her silver medal. According to IOC policies, athletes who receive more than a six-month sanction from their sporting federations for doping violations are shut out of the next Olympic Games.
Perhaps the strangest doping case this year was the suspension of four horses and their riders from Olympic show jumping after preliminary tests revealed a derivative of chili peppers, which is used to treat horse injuries, had been applied to the horses' skin. The chili pepper derivative is banned because it can be a mild stimulant.
So far, none of the athletes caught during the Olympics have come from the U.S. team, which U.S. Olympic Committee spokesman Darryl Seibel attributed to a get-tough approach to the problem.
U.S. Olympic athletes routinely rotate onto three-month shifts in which they can be tested without advance warning at any time. Law enforcement agents also help investigate athletes for drug use.
"We have no higher priority than clean competition," Seibel said. "You can't stand still. You have to constantly evaluate your program and it has to be forward-leaning and continue to adjust and adapt."
U.S. hurdler David Oliver, who won a bronze medal in Beijing, said audiences were overcoming their suspicions, however, and learning to believe performances such as Bolt's were possible without chemical assistance.
"People need to upgrade their minds and perceive what they see as impossible being possible," Oliver said. "Someday, what we do now in an extraordinary performance will be ordinary."