The Daily Mail are reporting that Mo Farah missed two drug tests in the lead up to the London 2012 Olympics.
The news comes in the wake of Farah's coach Alberto Salazar and training partner Galen Rupp facing a series of doping allegations.
Farah is reported to have first missed a test early in 2010, six months before breaking the British 5,000m record. He missed a second test in February 2011, shortly after commencing work with Salazar.
Salazar is then quoted as telling Farah in May 2011: "If you miss another test, they will hang you."
The report then publishes e-mails apparently exchanged between UK Anti-Doping's lawyers and Farah's representatives in which the lawyers say: "Intent and negligence are not the same thing, though, as I am sure you have advised him.
"The simple fact with this Missed Test is that your client says that he did not intend to miss the test, but it is clearly his own fault that he did."
The double Olympic champion, who won gold in the 5,000m and 10,000m at London 2012, contested the second missed test with the UK Anti-Doping Agency. His explanation was that he didn't hear the doorbell in his Teddington home when the testers called.
Three missed tests, under UK anti-doping rules, can potentially result in an athlete being banned for four years.
Farah's Irish agent Ricky Simms supplied video evidence of Farah's home to the UK Anti-Doping Agency in an effort to show the difficulty of hearing the doorbell from Farah's bedroom; however, that evidence was discounted by the agency's lawyers and the missed test stood as such.
Donegal man Simms also complained that the agency's lawyers were uncooperative.
Farah has kept a low profile since allegations against his coach Salazar surfaced, training without his US-based coach in France. Farah will run in the Monaco Diamond League meeting on 17 July.
Salazar is being accused of a host of doping offences, including giving Rupp, who finished second to Farah in the 10,000m at the London Games, testosterone at 16-years-old.
In addition, it's alleged that 17 witnesses have come forward with evidence of Salazar's doping system used at his Oregon base.These witnesses claim to have found unmarked vials and unused hypodermic needles in apartments and cars used by both Salazar and Rupp.
Farah announced on Wednesday he would return to the track for the first time since the doping allegations against Salazar emerged at the Monaco Diamond League meeting on 17 July.
He pulled out of the Sainsbury's Birmingham Grand Prix earlier this month, stating he was "physically and emotionally drained" by the affair.
Rather than racing in Birmingham, the 32-year-old jetted back to his Portland home to seek answers from Salazar.
On Wednesday he was back on the other side of the Atlantic, posting on Twitter a picture of himself training in France.
He said: "Good to be out on the track in France today, getting ready for my next race in Monaco!! Focusing on my training!!!!"
A week after competing at the Herculis meeting in Monaco, Farah is due to race at the Sainsbury's Anniversary Games at the Olympic Stadium.
