Pat McQuaid yesterday hit back at disgraced Tour de France winner Floyd Landis' accusations that as head of the sport's world governing body, the Union Cycliste International (UCI), the Wicklow man has protected top riders by covering up positive dope tests.
McQuaid labelled the American 'a liar' as he responded to comments made by Landis on German state television channel ARD on Sunday night.
Landis became the first Tour de France winner to be disqualified after he failed a dope test for testosterone during the 2006 event.
Having denied doping for four years, the American recently admitted the use of performance enhancing drugs and has already spurred a federal investigation into the activities of his former team-mates -- with claims of systematic doping within the Lance Armstrong-led US Postal team.
Landis also said the use of clenbuterol and other drugs was widespread in the sport and that he believed the UCI were covering up for cycling's top stars.
Landis also cast doubts on this year's Tour de France winner Alberto Contador, who is currently fighting a battle against a two-year suspension for minute traces of clenbuterol found in his system on the second rest day of this year's race.
"You don't know what risks people will take to win a race," Landis said. "I know that riders have taken Clenbuterol. I think that the risk of taking Clenbuterol is higher now than it was earlier, when there weren't any training controls.
"Nevertheless, there is still the risk of being caught, even if it is rather small now, since the product has usually degraded when the control takes place."
Landis went on to accuse McQuaid and his predecessor Hein Verbruggen of protecting top riders from a positive test result.
"It is known in the peloton that Pat McQuaid, Hein Verbruggen and others responsible at the UCI over the last 20 years have protected some people and not others," added Landis.
"That is the way they manipulate results and create stars. As far as the UCI is concerned, nothing about a cover-up or taking a bribe or some kind of race results manipulation would surprise me."
McQuaid is considering taking legal action over the claims and said: "It's very easy for Floyd Landis to make statements like that with no proof.
"Also, the journalist who interviewed him should have asked him for proof.
"He has already proven to be a liar and continues to be a liar. There is no truth in it, absolutely no truth in it."
McQuaid went on to confirm that both the UCI and the World Anti Doping Authority (WADA) get the same reports from anti-doping tests and says it would therefore be "impossible to protect riders".
"All you have to do is look at the amount of big names that have been found positive over the years to show that I don't protect anybody and the UCI doesn't protect anybody," said McQuaid from his base at UCI headquarters in Switzerland.
"Landis won the Tour and we went after him, Rasmussen was a Tour leader and we went after him, and now Contador. Landis talks about clenbuterol being used. We've gone after Contador with only 50 pictograms of clenbuterol in his system. This again proves that Landis' statement is complete fabrication."
When asked about his credibility on the German show, Landis added: "You do not have to believe me. I should not have lied the first time. I want cycling to improve but it doesn't matter to me if the world believes me or not."