Athletics: Olympic officials have promised the biggest drug-testing programme in the history of the games in a blitz on athletes using the new designer anabolic steroid tetrahydrogestrinone (THG).
Athens was already set to launch random testing on an unprecedented scale to catch drug cheats in the run-up to next year's games before it was announced that scientists in Los Angeles had identified the previously undetectable THG.
Britain's Dwain Chambers, the European 100 metres champion and record holder, faces a minimum two-year ban after he tested positive for the drug in an out-of-competition test in Germany in August.
UK Athletics will begin disciplinary action formally next week if the B test on the Londoner's urine sample matches his A test. It is rare that the second sample does not match the result of the first.
Chambers is one of four athletes publicly identified as having failed tests for THG. John McEwen, a little known hammer thrower who finished second in the US championships in June, is the latest to have been revealed to test positive for the drug.
He joins his fellow Americans Regina Jacobs, the world indoor 1,500 metres champion and record holder, and Kevin Toth, the national shot put champion.
However, it is believed at least one more major American name and several international names have failed tests for THG and are yet to have their identities revealed.
The International Olympic Committee (IOC) is in the process of informing its 31 accredited analysis laboratories around the world of the protocol for testing for the presence of THG, discovered by Dr Don Catlin at the University of California, Los Angeles.
"This shows the fight against doping is efficient," said Denis Oswald, the head of the IOC's coordination commission, during a visit to Athens to check on preparations for the games. "It's really a priority of the IOC. We will make every, every effort to test the athletes and to make sure the cheaters will not take part in the games.
"You say big stars (may be missing), but to me they are not stars if they cheat. The gap between the science and the cheater is getting narrow. I'm confident that the games will be clean."
Olympic organisers started carrying out 4,150 tests in August. During the games some 3,000 tests are planned, with 500-600 outside competition. For the first time random tests will be conducted for the blood-boosting drug EPO (erythropoietin), with 600 scheduled.
"If the system works as it should prior to games time we hope to have got the cheats before the games begin and have a clean Olympics," said Panayiotis Tsaourchas from the 2004 Olympics anti-doping agency.
Tsaourchas said wrestling, weightlifting, judo and athletics would be the main targets of his team. "The greatest difference with previous Olympics will be in terms of the volume of testing," he said.
Meanwhile, in San Francisco, the opening day of the US grand jury hearings into the man allegedly at the centre of the THG scandal, the nutritionist Victor Conte and his Bay Area Laboratory Co-operative, passed without any sportsmen or women being seen to enter or leave the federal court building where the closed sessions are being held.
Another big name of American sport, the boxer Shane Mosley, yesterday joined the list of those known to have been subpoenaed to testify. Mosley last month beat Oscar de la Hoya for his WBC and WBA junior-middleweight titles, after which, his lawyer pointed out, he was tested for 25 different steroids and masking agents "and came back completely clean".
Cycling at least claimed a small victory when the world governing body, the UCI, announced that all urine samples taken from riders at this month's world road championships in Canada came back negative. It condemned the "most regrettable speculation from part of the press" that the new world champion, Igor Astarloa, and five other high-profile riders were suspected by the UCI itself of using EPO.
