The Dane, who has admitted he doped throughout his 12 year professional career, claimed in his new book Yellow Fever he had taught Hesjedal, among others, how to take the banned blood-booster Erythropoietin (EPO) in 2003.

Hesjedal, who began his career in mountain biking, was a development rider with the same Radobank team as Rasmussen at the time.

Hesjedal, 32, responded to the allegations by admitting that "more than a decade ago" he had "chosen the wrong path".

"I sincerely apologise for my part in the dark past of the sport," he said.

"To everyone in my life, inside and outside the sport - to those that have supported me and my dreams - including my friends, my family, the media, fans, my peers, sponsors - to riders who didn't make the same choices as me all those years ago.

"Even though those mistakes happened more than ten years ago, and they were short-lived, it does not change the fact I made them and I have lived with that and been sorry for it ever since.

"I believe that being truthful will help the sport continue to move forward, and over a year ago when I was contacted by anti-doping authorities, I was open and honest about my past."

Ryder Hesjedal on the way to winning the Giro dItalia in 2012...he has admitted doping nine years earlier



As a cross country mountain bike rider Hesjedal won a silver medal at the 2003 World Championships and competed at the Olympic Games in Athens the following year.

At the same time he was a development rider with the Radobank team and made the full time switch to the road in 2005.

After a period a steady improvement, he became the first Canadian to compete in the Tour de France for more than a decade in 2008.

The following year he won Stage 12 of the Vuelta a Espana before a sixth place overall finish in the 2010 Tour de France.

His greatest success came in 2012 when he showed marked improvement on the climbs to claim a surprise victory at the Giro d'Italia.

He had never previously been directly implicated in doping although was last year called to testify by the US Anti-Doping Agency (USADA) in the case against Lance Armstrong, before the American was stripped of his seven Tour de France titles for doping.

After leaving Radobank, Hesjedal had been a teammate in 2004 and 2005 of Armstrong with the US Postal team, where doping was widespread.

His cooperation in this was confirmed by USADA chief executive Travis Tygart.

"We can confirm that USADA, along with the Canadian Center for Ethics in Sport (CCES), interviewed cyclist, Ryder Hesjedal, earlier this year as part of our ongoing investigation into the sport of cycling," said Tygart.

"Athletes like him, and others, who have voluntarily come in, taken accountability for their actions and have been fully truthful, are essential to securing a brighter future for the sport of cycling."

Hesjedal also rode for the US Postal Service team, pictured here before his arrival in 1999, and gave evidence against former teammate Lance Armstrong to the USADA last year



The Canadian has also received support from his current team, Garmin Slipstream, who praised his honesty.

"As we have previously stated, our expectation is that anyone in our organisation contacted by any anti-doping authority must be open and honest with that authority," said a Garmin statement.

"Ryder is no exception and a year ago when he was contacted he cooperated fully and truthfully testified to USADA and the Canadian Centre for Ethics in Sport.

"For this reason and because of our desire for 100 per cent truth and reconciliation in the sport of cycling, we support him."

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