Mo Farah missed two drugs tests in the run up to the Olympic Games in which he won gold in the 5,000m and 10,000m it has been claimed.
The Daily Mail report the distance runner failed to take one in 2010 and another the following summer after joining forces with coach Alberto Salazar who is currently battling allegations of doping made in a TV documentary.
A third would have meant a possible two-year ban which would have excluded him from London 2012 which was the defining point of his career.
The claims against Salazar allege he used doping techniques on American runner Galen Rupp, who was second in the 10,000m race which Farah won.
The UK Anti-Doping are to issue a statement on Thursday in relation to the matter.
Despite the missed tests and the allegations against Salazar there is no suggestion that Farah has been involved in doping.
Every time I hear it repeated "Mo Farah missed 2 tests", it suggests he skipped them purposefully. Now, he may have done. But we don't know— owenslotTheTimes (@owenslot) June 18, 2015
According to the Mail, Farah claims he missed the second test which was scheduled to take place at his home because he couldn't hear the doorbell ring.
As part of an appeal, Farah’s agent Ricky Simms, produced a video demonstrating how the sound carried from the front door to his bedroom.
Brit Christine Ohuruogu missed three doping tests in 2006 and was suspended for a year.