(CNN)Four-time Olympic gold medalist Mo Farah is under the spotlight for injections he received ahead of the London Marathon in 2014.
An investigation by BBC's Panorama, entitled "Mo Farah and the Salazar Scandal," raises renewed questions over Farah's relationship with former coach Alberto Salazar, who is appealing against a four-year ban for doping violations which he denies.
Farah was tested six days after receiving the injections. He recorded a number of medicines but failed to note L-carnitine on his doping control form, according to the Panorama investigation. When drug tested, athletes are required to note all the medicines and supplements they have taken within the past seven days.
The program also alleged that Farah repeatedly denied taking L-carnitine injections ahead of the London Marathon when questioned by US Anti-Doping Agency (USADA) officials in 2015, only to return minutes after the interview had concluded to say he did in fact receive the injections.
L-carnitine is a naturally occurring amino acid that enhances athletic performance. It is prohibited to have infusions of more than 50ml in the space of six hours.
Farah changed his account after speaking with UK Athletics' (UKA) head of endurance Barry Fudge, who had been interviewed by USADA the previous day, according to Panorama.
Farah then immediately returned to the USADA officials he had just been interviewed by to clarify that he had received injections.
His lawyers said in a statement that the athlete "understood the question (from USADA officials) one way and as soon as he left the room he asked Mr. Fudge and immediately returned ... to clarify and it is plain the investigators were c