Under British Olympic Association rules, Mr Chambers would be banned from Olympic participation for the rest of his life. A second sample is yet to be tested and Mr Chambers' coach, the California-based Ukrainian Remi Korchemny, has denied the offence, as has Mr Chambers' lawyer. Nonetheless, it is bad news, and not just because Mr Chambers represented this country's best hope of coming back from next year's Olympics with a gold medal in the 100 metres event. For Mr Chambers is hardly alone - 1,000 recent samples from British and German sportsmen and women are now to be retested, while 20 American athletes tested positively for THG at the American championships in June. These cases highlight some very disturbing and difficult issues facing competitive sport played at its highest levels. David Howman, the director-general of the World Anti-Doping Agency, claims that the "designer" steroid phenomenon could prove to be as sensational as the drug scandals in East Germany 30 years ago.The most uncomfortable truth facing the sporting authorities, and especially those running international athletics, is that so-called designer drugs are increasingly sophisticated and specifically concocted with a view to evading the latest detection techniques. It is precisely analogous to the ancient and constant battles between the printers and forgers of banknotes.The criminals will always, or at least very often, be one step ahead of the forces of law and order. Today a successful athlete on the world stage has every chance of becoming a millionaire, possibly many times over.

As Lyn Davies, a former Olympic long jump champion and the president of UK Athletics acknowledges, the motivations and temptations for top class athletes are understandable, even though episodes of abuse are disappointing.The fading image of athletics as a "clean" sport also damages its future in a more insidious way. Parents will inevitably become more wary before blessing a child's athletic ambitions if there is a danger that they will be exposed to strange undetectable drugs. There is also the point, obvious, but still worth mentioning, that cheating with steroids is unfair on those who choose to rely on their natural gifts.These observations do not render competitive athletics an entirely redundant activity, but fans should be aware that, unfortunately, what they are watching in the stadium or on the television may not represent the purest of sporting contests.Unfortunately for athletics, there are already signs the public is losing interest in the sport Television ratings are falling. This summer, the World Athletics Championship left BBC1 with record low viewing figures, an experience that the corporation will not wish to repeat.

In that context, then, the task for the authorities is to minimise the damage that these inevitable periodic scandals do to the credibility of athletics. That must mean exemplary punishment for those found guilty of drug abuse. The British Olympic Association's lifetime ban is a serious sanction, and one that has to be invoked without hesitation in cases of clear guilt.So, the athletics authorities and, sporting organisations generally, have to be tough on drug abuse and tough on the causes of drug abuse. They have to perfect methods of detection, the fear of getting caught being the greatest deterrent against wrongdoing. They have to match financial temptations with harsh punishments. They should play a more active role in criminal investigations. Even so, we may soon have to talk of the "pre-THG" and "post-THG" eras in international sport..