But MPs on the digital, culture, media and sport committee said Wiggins may have been treated with triamcinolone up to nine times over a four-year period. 'It would be hard to know what possible medical need could have required such a seemingly excessive use of this drug,' they said.
The committee's explosive report also revealed that Wiggins' former coach Shane Sutton had told the MPs the cyclist's use of triamcinolone was 'unethical'.
And it raised the prospect of other British cyclists being involved, saying that Team Sky, the country's elite cycling team, used drugs to 'enhance the performance of riders and not just to treat medical need'.
The MPs accused the team of crossing an 'ethical line' in its conduct, raising questions over the role of its boss Sir David Brailsford.
The report will send shockwaves through world of British cycling and deal a massive blow to the reputation of Wiggins, who became the first British cyclist to win the Tour de France just over a week before winning gold at the London Olympics.
He was knighted by the Queen a year later.
But Wiggins' status as a national hero began to come under threat when the Mail revealed two years ago that he received a medical package before a race in 2011 – a jiffy bag that allegedly contained triamcinolone.
Now the devastating Commons report – which credits the Mail for bringing the issue to light – has piled more pressure on the cyclist and the conduct of Team Sky. It also raises questions for two other British Olympic heroes.
It found that:
- Sebastian Coe, president of the International Association of Athletics Federations, 'misled' MPs when he said he did not know about Russian doping until the end of 2014;
- The double Olympic champion, who sits in the House of Lords, was accused of 'stretching credibility' with his statements;
- The behaviour of the IAAF suggests it has an 'apparent desire to suppress revelations about doping in sport';
- Sir Mo Farah received a dose of L-carnitine before the 2014 London Marathon to 'improve his performance', and England's team doctor, Robin Chakraverty, should be investigated by the General Medical Council over his failure to report the injection.
The scandal centres on Wiggins' use of the drug triamcinolone, a type of corticosteroid. Team Sky, Britain's cycling team, have always claimed it was used to treat asthma.
Wiggins has claimed the drug did nothing more than put him 'back on a level playing field' with his rivals.
But triamcinolone can induce weight loss and improve a cyclist's pain threshold. It is usually banned, but athletes can ask for a 'therapeutic use exemption' (TUE) to allow them to use it if they come down with another condition – such as asthma.
The MPs' report said: 'We believe that this powerful corticosteroid was being used to prepare Bradley Wiggins, and possibly other riders supporting him, for the Tour de France.
'The purpose of this was not to treat medical need, but to improve his power-to-weight ratio ahead of the race.
'The application for the TUE for the triamcinolone for Bradley Wiggins, ahead of the 2012 Tour de France, also meant that he benefited from the performance-enhancing properties of this drug during the race.
'This does not constitute a violation of the World Anti-doping Agency (WADA) code, but it does cross the ethical line that David Brailsford says he himself drew for Team Sky.
'In this case, and contrary to the testimony of David Brailsford in front of the committee, we believe that drugs were being used by Team Sky, within the WADA rules, to enhance the performance of riders, and not just to treat medical need.'
The committee also said there was serious doubt over Team Sky's claims that Wiggins did not take triamcinolone before the previous year's Tour de France in 2011.
While Wiggins had a TUE exemption in 2012, he did not have one the year before. Team Sky have always claimed the drug he was delivered in a jiffy bag in 2011 was the legal Fluimucil.
The MPs cast doubt on this explanation, but said it was not possible to come to a firm conclusion because Team Sky doctor Dr Richard Freeman did not keep records.
Dr Freeman, who has since resigned his post at British Cycling, is being investigated by the General Medical Council for not keeping proper medical records. The MPs called for WADA to bring in a complete ban on the use of corticosteroids. The report also revealed that Wiggins' former coach Sutton told them: 'What Brad was doing was unethical but not against the rules.'
Last night Wiggins said: 'I find it so sad that accusations can be made, where people can be accused of things they have never done which are then regarded as facts. I strongly refute the claim that any drug was used without medical need. I hope to have my say in the next few days and put to my side across.'
Team Sky said: 'The report details again areas in the past where we have already acknowledged that the team fell short. We take full responsibility for mistakes that were made. However, the report also makes the serious claim that medication has been used by the team to enhance performance. We strongly refute this.
'The report also includes an allegation of widespread triamcinolone use by Team Sky riders ahead of the 2012 Tour de France. Again, we strongly refute this allegation. We are surprised and disappointed that the committee has chosen to present an anonymous and potentially malicious claim in this way, without presenting any evidence or giving us an opportunity to respond.
'This is unfair both to the team and to the riders in question.'
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