SOME 2012 Olympic competitor, somewhere, this very day, is on a drug-fuelled charge to London.

It won't be just one. Several men and women will take banned performance-enhancing substances or plan to do so. Not all will be caught.

Indeed, some may win medals. There may even be podium success for offenders who previously failed dope tests but are now reinstated – former 100 metres champion Justin Gatlin, or defending 400m gold medallist LaShawn Merritt, perhaps. Or world and European medallists such as cyclist David Millar and sprinter Dwain Chambers.

Not that we suggest this quartet are still members of the brotherhood of the needle. Testers sometimes arrive at their doors before breakfast, but, no matter how scathing the scandal, or how scalding the shame, history tells us that some will take the risk. Only two of five Olympic 100m champions since 1988 remain untainted: Donovan Bailey (1996) and Usain Bolt (2008).

Don't just take my word that cheats will be about their business today. I talked to William Hill yesterday, and the bookmakers suggested that, when they got down to formalising their odds, the chance of a completely clean Games in London would be at least 100-1. Even at 1000-1, only the most optimistic speculator might risk a sniff.

It's with sorry cynicism that we contemplate the reality of sport, the nature of (and attitudes to) the dream thieves whom the media promote to heroes. And, in particular, to the most notorious Olympic cheat of all.

It is almost 24 years, but the moment remains freeze-framed, stark and clear: Ben Johnson, the heavily muscled right arm aloft, forefinger raised, crossing the line, then glancing left to seek US arch- rival Carl Lewis as he beat him for the 1988 Olympic 100m gold . . . more than a metre of daylight between them . . . the clock stopped at a world record-breaking 7.79 seconds . . . the jaw-sagging amazement and, yes, downright disbelief of pressbox colleagues as we exchanged knowing glances and unspoken doubts.

It speaks volumes that, almost a quarter of a century after this race lasting less than 10 seconds, it can fill a whole new book, and still generate strong passions and controversy.

The Dirtiest Race in History*, published this week, is a remarkably fresh read given the amount of ink already spilled on the topic. Author Richard Moore has delivered what is certainly the most comprehensive account, and as close to definitive as possible without giving all the "answers".

Sport, it seems, needs villains. "Infamy, infamy – they've all got it in for me," as Kenneth Connor, a suitably ridiculous Caesar, so memorably intoned. Johnson sometimes cut a pantomime figure against Lewis, but there will be no applause at the Canadian's final curtain call. Obituaries will surely portray a sporting pariah.

Is this fair? As we contemplate the possibility of Chambers and Millar sporting TeamGB kit in London, I will be surprised if they are other than well received. Not for them the leperous stigma Johnson has endured. This is most curious.

Consider Americans Mike Stulce and Jim Doehring, and Russian Vyacheslav Lhyko. Who? Thought so. They comprised the 1992 Olympic shot putt podium. All three had previously been convicted of doping offences and were reinstated to sweep the medals in Barcelona. I recall no booing.

Why the ambivalence?

Let's be clear. I deplore what Johnson did, but feel awkward at his continuing demonisation.

Moore's book poses almost as many questions as it answers. He sets hares running around the enigmatic Andre Jackson – now chairman of the African Diamond Council but then a friend of Carl Lewis.

Curiously, he became Johnson's drinking buddy – a man who passed Johnson several beers in the doping control room after the race, a man who at the time was staying with Lewis, and the man whom Johnson claims in his book spiked his drink. A second figure with a foot in both camps was the late Jack Scott, of whom it might also be said there was motive and opportunity.

Johnson's litany of claims down the years discourage credibility. Yet he took seven years even to recall Jackson's name. Lewis' book even contained a picture of Jackson with Ben in that doping room and some new responses from Lewis' manager, Joe Douglas, will encourage conspiracy theorists.

Canada's Dubin Inquiry found Ben an intellectual lightweight and convenient scapegoat. That was perhaps counter-productive in establishing the scope of systematic organised doping, though it established his handlers as serial manipulators.

This book neither clears Johnson but nor does it demonise him. Perhaps it's time the world stopped demonising him, too.

Dirtiest race? No argument. Only two of that 1988 final field –Calvin Smith (who ultimately was presented with bronze in the anonymous bowels of the Chamshil stadium) and the Brazilian Robson da Silva (fifth) – remain free of drug allegations or positive tests.

Lewis, who inherited gold, gave a positive sample at the US trials for Seoul but it was hushed up. Linford Christie, promoted to silver, was given "the benefit of the doubt" over a failed test in Seoul, but eventually served a two-year steroid ban. Both are millionaires.

Today, Smith is a social worker, and believes he was the rightful champion – unquestionably a bigger victim than Johnson.

*The Dirtiest Race in History, by Richard Moore, Bloomsbury, £18.99.