Paris - The US anti-doping agency USADA explained on Tuesday why it had withdrawn charges that could have seen American sprinter Christian Coleman face a two-year ban.
Drug-testers filed the charges after they were unable to locate Coleman, the fastest man over 100m this year, on three separate occasions in what they believed to be a 12-month period.
But after looking at the rules and taking advice from the world doping authority WADA Coleman is now free to take part not only in the upcoming Doha World Athletics Championships), but also in the Tokyo Olympics next August.
Athletes must provide a location where they can be found and a 60 minute window of time where they can be tested without forward notice for every day. They must record this information on an IAAF software (called Adams) every three months.
If a tester travels to the place at that time and the athlete is not present this is considered a no show. But the athlete can also be penalised if the tester is simply unable to locate the athlete due to substandard instructions, which is called a 'filing failure'.
After three missed tests in 12 months a disciplinary hearing is held and a two-year ban recommended, or a one-year ban in extenuating circumstances.
USADA said it had first recorded a "whereabouts failure" against Coleman on June 6 last year.
A doping control officer had attempted to test the sprinter and discovered that he had failed to update his whereabouts information to accurately reflect his location.
Two more whereabouts failures were also logged on January 16 this year and April 26.
However, on closer inspection of the rules USADA had recorded a date of April 1 for the first infraction because in the case of a filing failure, the date of the filing is used and not the date of the attempted test.
The world athletics body IAAF can appeal if they wish.
They say they switched the date from June 6 to April 1: "After receiving guidance from the World Anti-Doping Agency (WADA) on the interpretation of the current International Standard for Testing and Investigations (ISTI) concerning the date on which a failure to update an athlete's changed whereabouts information should be considered to have occurred."
"As a result of this interpretation, Coleman is not considered to have three whereabouts failures in a 12-month period and is not considered to have committed an anti-doping rule violation.
USADA said Coleman had since provided his whereabouts information by the start of each quarter as required and had been tested by the agency on 20 separate occasions.
The sprinter had been due to face a hearing on Thursday which has now been scrapped, USADA said.
The agency said Coleman was free to compete with immediate effect but noted that the decision to withdraw the case could still be appealed by the International Association of Athletics Federations (IAAF).