The US Anti-Doping Agency charged Coleman with missing three tests in 12 months before withdrawing the claim.

The American, 23, said he has "never failed a drug test and never will".

Asked whether the situation would overshadow anything Coleman achieved at the World Championships in Doha, Johnson said: "I think it will."

He added: "He didn't do himself any favours the way he handled that situation."

Coleman ran 9.81 seconds in the 100m at the Diamond League in California in June, the fastest time in the world this year.

The charge against the American, who faced an automatic one-year ban, was withdrawn after the US Anti-Doping Agency (Usada) received guidance from the World Anti-Doping Agency (Wada).

"It's simply disrespectful when fake fans speculate and talk about drugs in relation to the great athletes we have in this sport," wrote Coleman on social media.

"It does nothing but hold the sport back from the popularity I know it can reach in the future."

Usada said Coleman had missed drugs tests on 6 June, 2018, 16 January, 2019 and 26 April, 2019 - with three missed tests in a 12-month triggering a ban.

However, as the International Standard for Testing and Investigations (ISTI) says a "filing failure" - failing to update details of the athlete's daily whereabouts - should be deemed to have occurred on the first day of the quarter, Coleman argued the first of those failures should be 1 April, 2018, meaning he did not have three failures in 12 months.

"Let's be clear, Usada made a huge mistake by bringing a case against him when their own rules basically state that he had two, not missed tests, but whereabouts violations, as opposed to the three, and they then had to withdraw their case against him," former Olympic 200m and 400m champion Johnson told the BBC Breakfast Show.

"In fairness to Christian Coleman, there is a huge difference between positive tests - or even missing tests - and this situation.

"But if you are going to position yourself as the face of the sport and the superstar of the sport, you have a responsibility to always update your whereabouts and not make the mistake that he did in not updating that those three times and then handling it the way that he did after it came to the public view."