The agent of joint 100m world record holder Asafa Powell has pledged that the Jamaican is not using drugs.
Powell was "upset" to hear Gatlin had failed a drugs test
Powell shares the record with American Justin Gatlin, who admitted on Saturday that he had failed a drugs test.
Powell's agent, Paul Doyle, told BBC Sport he realised questions would be asked about his client, but could guarantee he did not use illegal drugs.
"I sure can. Absolutely. Asafa Powell is a clean athlete. He does not take drugs," Doyle told Radio Five Live.
Powell had been hoping for a head-to-head race with Gatlin this summer, and Doyle said his client was unhappy to hear of Gatlin's positive test.
"He was quite surprised," Doyle said, "a little bit upset by the news.
"He had a lot of questions - how did this come about, how did I hear about it, all that. But, of course, the first thing he wanted to know was, was it true?"
Ben Johnson, who was stripped of Olympic gold and the world record in 1988 after failing a drugs test, said he thought the public were not concerned about whether athletes were on drugs.
When it becomes public that an athlete as high-profile as Justin Gatlin has tested positive, at least we know there are no cover-ups happening
Asafa Powell's agent
"The spectators don't care," the Canadian said. "The sponsors don't care. All they want to see is the world's fastest man - if he's running in 9.7 seconds, 9.8, whatever it is.
"That's the way life is, and people have to come to terms with that and live with it and just enjoy track and field."
But Doyle said: "That's the way people who take drugs try to justify it."
Speaking before confirmation that Gatlin's back-up sample confirmed the positive test, he said Gatlin should be banned for life if that was the case.
Athletics' governing body has already confirmed that penalty would be imposed if Gatlin is found guilty.
"If the positive A sample is confirmed, he should be banned," Doyle said.
Johnson (left) says the public don't care if people cheat
"I believe that anybody that tests positive and they're convicted for taking drugs should be banned for life - even one offence."
And he said that while high-profile doping cases were bad news for athletics in the short-term, they were a positive overall.
"When an athlete gets banned, it's a good thing in the long run because it means we are cleaning up the sport," Doyle said.
"We're taking a step in the right direction even if in the public eye it may be marred a little bit.
"When it becomes public that an athlete as high-profile as Justin Gatlin has tested positive, at least we know there are no cover-ups happening - not that I can comment specifically about Justin's innocence."