Christian Coleman arrives at the World Championships as the heavy favourite for 100m gold after an impressive season that has seen him clock a world-leading 9.81sec.

But while the 23-year-old has left most of his rivals trailing firmly in his slipstream this year, he may find sceptics harder to shake off.

In the eyes of many, Coleman, the 2017 World Championships silver medallist over 100m, is extremely fortunate to even be competing in Doha.

In August, the athletics world was rocked by news that Coleman had registered three drug-testing “whereabouts” failures in a 12-month period – an offence usually regarded as equivalent to a failed drug test and followed by a ban of up to two years.

Yet with Coleman facing the very real possibility of a suspension that would have barred him from competing at the World Championships and next year’s Olympics, the case collapsed this month because of a technicality.

At first glance, it appeared to be an open and shut case. Coleman had recorded his first whereabouts failure on June 6 last year, before two more offences in January 16 and April 26 this year.

However the United States Anti-Doping Agency abruptly withdrew the charges against Coleman on September 2 after a review of the rules regarding how the 12-month window should be calculated.

Under an obscure regulation in the International Standard for Testing and Investigations guidelines, Coleman’s first missed case in June last year should have been backdated to the first day of that quarter, making the formal date of the first offence April 1, 2018.

‘Nobody’s perfect’

That meant the dates of the three offences fell outside the required 12-month time frame for a doping offence to have occurred – leaving Coleman in the clear and free to compete in Doha.

Coleman responded to the news by demanding an apology from Usada, accusing the anti-doping body of smearing his reputation and insisting he had always been a clean athlete.

“I have never failed a drug test and never will,” Coleman said. “It’s a shame on Usada that this was public knowledge, that they didn’t know their own rules – that they expect athletes to know the rules but they can’t follow their own.”

Coleman explained away the three whereabouts failures as simply innocent mistakes, blaming his anxiety and last-minute schedule changes for his failure to update his location information.

“People don’t realise how easy it is to miss tests,” Coleman said. “People out there calling me an idiot, or I’ve gotta be stupid to miss tests. I don’t know what people look at athletes at, but nobody’s perfect. People make mistakes.”

The wider athletics world, however, is likely to view those protestations of innocence through a prism of scepticism.

Privately, anti-doping officials say that while athletes can often miss individual tests, it is largely unheard of for an athlete to miss three.

“We do everything we possibly can to ensure this kind of thing doesn’t happen, and we make it as easy as possible for athletes to notify us of changes in their schedule,” one official said.