Controversy surrounding Mo Farah and his involvement with coach Alberto Salazar intensified last night. The Daily Mail have revealed that Farah missed two drugs tests in the build up to London 2012.

Farah, who won the 5,000 and 10,000 metres titles in London three years ago missed his first test early in 2010. He joined Salazar's training camp in Oregon the following year and the Daily Mail reports that the second missed test came that summer.

The Olympic champion claimed to be at home in London, but was unable to hear the doorbell when he was resting in his bedroom. UK Athletics rules at the time stated that if any athlete missed three drugs tests in an 18 month period, an athlete may face a four year ban. The rule has since been lowered from an 18 month period to 12 months.

If Farah missed another test in the build up to the 2011 World Championships he would have missed out on his home Olympics. In Daegu, Farah won the 5,000 metres gold medal and finished second in the 10,000 metres final.

Donegal native Ricky Simms, who is Farah's agent, gave video evidence regarding the second test trying to prove his clients explanation for the missed test was plausible. The evidence was struck out by UK Anti Doping.

Farah has been under pressure to disassociate himself from Salazar, since the American coach was the focus of a BBC documentary into doping cultures with athletes, including Farah's training partner Galen Rupp.