Tom Humphries/LockerRoom: We'll probably never know if Carl Lewis was a walking pharmacology unit or a pure athletic wonder and probably we'll never quite understand why most of us could barely suppress a smile last week when allegations about him resurfaced in the US.

Did we always wonder if somebody who played it so sweet could really be so wholesome? What do we know? We know though that what goes around comes around and even if you are inclined to give Lewis the benefit of the doubt (a fairness he has earned) there has to be a little morsel of satisfaction for you to savour in seeing one so graceless and churlish suffer a stain from his soiled sport. He was always free with the words and liberal with the arrogance. Something was always going to bite back.

If you've spent time looking into the wonderful world of doping you've come across fellow travellers who have spent good portions of their working lives trying to catch Lewis, people who swear they've come close enough to see him sweat.

Never a nailing though. Just stories and inferences and the suggestion that someday it might all add up.

Back in 1984, when Lewis announced himself with four gold medals in LA, he helped put the Olympics back together again. After Montreal, Moscow and even an Eastern Bloc boycott of LA the sound of cash registers whirring was music to the IOC's ears. Of course it was America and it was brash and Lewis was the symbol of it all. The old pecksniffian Euro-centrics on the IOC were at once both grateful and resentful.

Los Angeles threw up a marketable star like Lewis and it made a lot of money. And a day or so after the Games ended the IOC's medical director Prince Alexandre de Merode returned to his suite in the Biltmore Hotel and discovered, sacre bleu, that it had been converted back into regular rooms and all his documentation, including that for nine positive drug tests, had been passed back to the USOC.

In the years before his death de Merode claimed that a member of the LA organising committee, Dr Tony Daly told him first that the documents had been sent to Lausanne and then admitted that they had been shredded. Daly has always maintained that he knows nothing of such a conversation.

Whatever. The documents relating to athletics races in the final two days of the Games were gone forever. Somebody got clean away.

We'll never know anything more about what happened except that the ripples spread out slowly. De Merode claimed that he believed the disappearance to have been a genuine accident but the incident dented his credibility and in the years afterwards he lost no chance to get the knife into the Americans. In 1988 he alleged that five tests from the Seoul Games involving Americans had been suppressed.

But that allegation was hardly heard. The funny thing was that the legacy of the Biltmore Hotel vanishing spilled over into Seoul. Fearing that Ben Johnson's positive test might be destined for the "shredder", it was testers who leaked news of it to local media which forced the hand of the IOC.

Have you believed in sprinting since then? Did you believe before? Lots of people didn't believe back in 1983 in Indianapolis at the US Nationals when Carl Lewis ran 19.75 for the 200 metres, two-tenths of a second faster than the previous sea level record. What astonished was that his last 11 strides were spent in celebration, waving his arms.

We don't know either what happened at the World Championships at Helsinki that year. There have been allegations since then that 38 athletes, including 17 Americans, tested positive but the names were too big to be disclosed without athletics shipping terminal damage.

Charlie Francis, sprint guru, coach to Ben Johnson and the frankest of sources when it comes to dope-speak drew some of his personal moral justification from another incident in 1983 when he was on hand in Los Angeles to witness a two nation meet between the USA and GDR. The GDR won with a team of beefed up automatons. This is what we are all up against concluded Francis. Was he the only one who drew that conclusion? The following year in LA the East Germans were missing because of a boycott and the Americans swept all 10 sprint events. In the 100 metres final Lewis' remarkable performance looked better and better when you watched it over again. The field fell away in the final 20 metres. Lewis kept moving like a god.

Through all those times the impression has been there that American athletics people speak with forked tongues when it comes to doping. The thought that Marion Jones and Tim Montgomery would have travelled to work with Charlie Francis recently and thought that nobody would demur seems only to underline the culture they felt they were working within.

Now the US Olympic Committee's director of drug control administration from 1991 to 2000, Dr Wade Exum, has spilled some more beans. Exum worked at the coal face for a long time. Starting out as an idealist, finishing up bitter and shorn of his illusions. He also finished up with 30,000 pages of documents in his possession. He says that they prove that the Americans ran a wilfully ineffective testing program which encouraged the use of performance-enhancing Drugs.

The papers instance more than 100 positive drug tests for US athletes from 1988 to 2000. In most cases the athletes were not prevented from competing. The documents contain test results, (in some cases memos or letters) which indicate positives for athletes who won 19 Olympic medals between 1984 and 2000. At least 18 athletes also who tested positive at US Olympic trials. They were permitted to compete in the subsequent Games.

Carl Lewis is the biggest name in the frame. It is alleged that at the 1988 US Olympic trials he tested positive, not once, not twice, but three times for small amounts of banned stimulants found in cold medications: pseudoephedrine, ephedrine and phenylpropanolamine. There's a CJ Hunter type of arrogance to that.

The USOC accepted Lewis's explanation that his use had been inadvertent.

In isolation it would be interesting but not that significant. However Joe DeLoach who was Lewis's training partner at the time, and who won the 200 at the '88 trials, also tested positive for the same three stimulants as Lewis and got off by using the same excuse. DeLoach won the 200 in Seoul.

In 1989, American Track and Field had to announce the "voluntary resignation" of Los Angeles coach Chuck deBus for alleged use of banned substances in training athletes and at the same time a former American 400 metre runner called Darrell Robinson claimed that in September 1982, while he was staying at Carl Lewis' home in Houston, he wandered into Lewis'bedroom as Lewis was just finishing being given an injection of a "whitish liquid" that Robinson believed to be the steroid testosterone. He also claimed that later in the same year he saw Lewis's coach, Tom Tellez, give athletes packets of blue pills. Robinson insisted that these were steroids.

Robinson made allegations against others, including Florence Griffith-Joyner, but his testimony was tainted by his links to Charlie Francis who actually drove him to the TV studio in Toronto where he recorded a segment for NBC.

So that's 20 years, a little more of rumours, anecdotes and shredded documents. Lewis, an icon of the sport, has been at the centre of so many of the great moments that's it's inevitable perhaps that he should be dragged into the murk.

Either he is an athlete soiled by his dirty sport or an operator who played the system with rare nerve. Either way if we are to do him and his sport justice we need to know more. If athletics has a hollow past than it can have no honest future.