Sprinters Tyson Gay (left) and Jamaica's Asafa Powell failed dope tests. Picture: Thomas Lohnes

London – As the nation relives the memories of the most glorious chapter in its sporting history, a big man throws a shadow across the weekend of London Olympic celebrations. His name is Asafa Powell, and he is a cheat.

Powell, once the holder of the 100metres world record, recently tested positive for the banned stimulant oxilofrine.

His reaction to the disclosure was chillingly pragmatic. Asked about his possible retirement, he said: “I’ve never once thought about giving up. I’m still training. I consider this an off-year, but I’m still working hard.

“It’s very unfortunate that I won’t be going to the world championships, but there’s a lot more to go. There’s a world championships in two years’ time again, and then the Olympics. So there’s a lot to look forward to.”

In some curious fashion, that reaction was more shocking than the positive test. As familiar headlines go, ‘Famous Sprinter Fails Drugs Test’ is on a par with ‘Famous Batsman Refuses to Walk’. But the cynical nature of Powell’s remarks seemed to set it apart.

Most people would have considered it a calamity, yet for Powell, it was no more than an occupational hazard: “An off-year”... “very unfortunate” ... “a lot to look forward to”.

He sounded remarkably like the safe-blower who weighs the potential reward against the severity of the sentence, then reaches for the dynamite. Cynical scarcely does it justice.

Naturally, he offered the standard justification for a failed test: he was just too trustful, people let him down, he was given nutritional substances by a newly employed physiotherapist. It is the sprinting equivalent of ‘The dog ate my homework’. Tyson Gay, equally famous and now equally culpable, is running a similar defence. And they trot this out in the knowledge that the probable penalty for a first offence involving a stimulant is three to six months’ suspension. Not so much a ban, more an irksome blip in their hectic careers.

Such demeaning capers will delight those who have always resented the success of London’s Olympic summer. They range from the disdainful curmudgeons who regard all sport as the pastime of sweaty oiks, to the dreary pontificators whose sporting horizons do not extend beyond White Hart Lane or Upton Park. Powell’s brazen response will merely confirm their prejudices.

Bit it would be a dangerous mistake to assume that drug abuse is confined to the major Olympic sport. The IAAF, governing body of track and field, carries out more tests than any other federation in the world, and it can boast a whole list of celebrated scalps. Other sports have their own arrangements, but a curious outsider might wonder at, say, the dramatically increased bulk of rugby players, or the stunning advances in the speed and stamina of professional footballers. They may well be above suspicion, as might professional boxing and tennis but, until they all test with the same intensity as athletics, we can never be quite sure. Yet track and field bears the stigma, and it will do so until it takes the necessary measures.

As Seb Coe argued in these pages last week, these offenders are trashing the history of their sport. In the regrettable absence of life bans, they should face mandatory four-year suspensions, with no leniency for first offences, no sense that stimulants are somehow less offensive than harder drugs.

Certainly, no athlete who fails a drugs test should be allowed to think in terms of a world championships or an Olympics down the line. For such cynicism is corrosive and, ultimately, no sport can withstand its baleful effects.

As the vast crowds gather in the Olympic Park this weekend, they want to enjoy the efforts of athletes who have gained their eminence through selfless dedication to their sport. They want to believe that the achievements which enthralled them 12 months ago were legitimately secured.

If that trust is dissolved, then their enjoyment is hopelessly compromised. At the moment, track and field is clinging to its credibility. One more high-profile revelation could seal its fate.

So the solution lies in the sport’s own hands. It must ruthlessly rid itself of the junkies and the parasites, the chancers and the cheats. The long-term banning of Asafa Powell would be an excellent way to start. – Mail on Sunday