LONDON • The whistle-blower at the centre of an investigation into Mo Farah's coach has claimed that the British Olympic champion still has questions to answer.

Steve Magness, Alberto Salazar's former assistant who was a guinea pig for tests of intravenous drip infusions of the legal substance L-carnitine, also questioned whether there was a conflict of interest over UK Athletics' (UKA) investigation of its links with Salazar.

Magness was speaking after a leaked report from the United States Anti-Doping Agency (Usada) said that Salazar "almost certainly" broke anti-doping rules by abusing prescription drugs and experimenting with infusions of L-carnitine, an amino acid that has been seen to reduce fatigue, at his Nike-sponsored Oregon base.

The report was obtained by The Sunday Times from the Fancy Bears hacking group.

Salazar has insisted he did everything within the rules and even sought guidance from Usada.

"If you are Mo Farah and you think it was clean and okay, then you have to come forward and lay the truth on the line," Magness said.

"If I was him I would want to be 100 per cent sure I am surrounding myself with proper and clean people."

Farah has insisted that he is totally clean and said he was frustrated he had been dragged into the controversy, but Magness told The Times: "There is a point where you have to take responsibility. Someone of his stature, who has done what he has done and been knighted, has to come forward and put all his cards on the table."

UKA set up a performance oversight committee in 2015 to conduct an independent audit of its links with Salazar's Oregon project, which did not report any evidence of inappropriate behaviour. Magness has alleged that the investigation was too narrow.

He added: "They have failed in the sense that it's their job to investigate these things properly in a fair way. Clearly it shows there is some conflict of interest preventing them doing so."

Asked what he meant, he said: "The relationship with Nike, the relationship with Salazar, the fact very high-up people in UKA were very close to Salazar and would fly over. If you look at it from the prescription drug (issue) and look at it from a health standpoint, then they have failed."

Magness added that Salazar's programme should be regarded as potentially worrying as the doping past of banned cyclist Lance Armstrong. He said: "I don't know if it was as blatant as Lance Armstrong but it is as concerning lots of other ways."

THE TIMES, LONDON