LOS ANGELES (AFP) - The Athletics Integrity Unit (AIU) on Wednesday (June 17) rejected world 100-metre champion Christian Coleman's complaints after it provisionally suspended him over a missed drugs test, putting him at risk of a ban that would rule him out of next year's Tokyo Olympics.

Coleman, who only narrowly avoided being banned last year after three violations of anti-doping "whereabouts" rules across 2018 and 2019, said in a long statement on Twitter that he was the victim of "a purposeful attempt to get me to miss a test".

"I was more than ready and available for testing and if I had received a phone call, I could've taken the drug test and carried on with my night," he said.

"I've been contacted by phone literally every other time I've been tested," said Coleman.

The AIU, World Athletics' anti-doping arm, responded in an e-mail to AFP in which they said "we will not comment on the specifics of an ongoing case" but wanted to make clear that "a phone call is discretionary and not a mandatory requirement".

"Any advanced notice of testing, in the form of a phone call or otherwise, provides an opportunity for athletes to engage in tampering or evasion or other improper conduct which can limit the efficacy of testing."

The 24-year-old is now barred from competition pending a hearing under World Athletics anti-doping rules, the AIU website said.

The news came 12 days after another 2019 world champion Bahrain's Salwa Eid Naser, winner of the women's 400m, was provisionally suspended for the same reason. It is another blow to the image of athletics, a sport trying to improve a reputation damaged by doping scandals, particularly in the sprints.

Coleman's two American predecessors as 100m world champions, Justin Gatlin, who won in 2005 and 2017, and Tyson Gay, 2007, were both banned for doping. Gatlin was banned twice and his second title came after he had served a four-year ban.

Coleman escaped suspension on a technicality ahead of last September's World Championships after it emerged he had committed three whereabouts failures in a 12-month period.

Those offences were recorded on June 6, 2018, Jan 16, 2019 and April 26, 2019.

Coleman successfully argued that the first missed case should have been backdated to the first day of the quarter - April 1, 2018 - meaning the three failures fell just outside the required 12-month period.

The world's fastest man last year, who clocked 9.76 seconds to win the 100m gold at the World Championships in Doha, said he had unsuccessfully challenged the latest AIU finding that he missed a test on Dec 9, 2019.

That missed test means that his offences in January and April of last year come into play.

Under World Anti-Doping Agency rules, any combination of three whereabouts failures - either missing a test or failing to file paperwork on time - within a 12-month period is deemed a doping offence punishable by a two-year suspension, which can be reduced to one year if there are mitigating circumstances.

Coleman said testers had visited his home when he was out shopping for Christmas presents nearby and he had bank statements and receipts to prove it.

"Don't tell me I 'missed' a test if you sneak up on my door (parked outside the gate and walked through...there's no record of anyone coming to my place) without my knowledge," Coleman said.

"And now this might result in me being suspended from other filing failures that occurred well over a year ago at this point."

His impassioned statement was accompanied by what appeared to be a copy of his formal notification from the AIU of a missed test.

"I was only made aware of this attempted drug test the next day on December 10th, 2019 by the AIU when I got this failed attempt report out of nowhere."

The report from the doping control officer posted by Coleman said the tester had arrived at his apartment but failed to get a response after "multiple, loud knocks were made every 10 minutes" for an hour.

No attempt to reach Coleman by phone was made, according to the document.

Saying that he had been phoned on every previous occasion, he asked "why this time was different?"

He said he was tested two days later and added: "I've been tested multiple times since, even during quarantine.

"But of course, that doesn't matter, and the fact that I have never taken drugs doesn't matter either."