Three-times Tour de France winner Greg LeMond has called on International Cycling Union (UCI) President Pat McQuaid to quit in the wake of the Lance Armstrong doping scandal.
American LeMond, who won the Tour in 1986, 1989 and 1990, wrote an open letter on his Facebook page on Thursday criticising McQuaid and his predecessor Hein Verbruggen, now honorary president of the UCI.
"I want to tell the world of cycling to please join me in telling Pat McQuaid to resign," LeMond, 51, said in an open letter on his Facebook page.
"Pat, I thought you loved cycling? At one time you did and if you did love cycling please dig deep inside and remember that part of your life -- allow cycling to grow and flourish -- please!," he added.
"It is time to walk away. Walk away if you love cycling."
LeMond is now the only American to have won the Tour after Armstrong was stripped of his seven titles and banned for life by the UCI on Monday as they ratified the United States Anti-Doping Agency's sanctions against the Texan.
USADA published a report earlier this month into Armstrong which alleged the now-retired rider had been involved in the "most sophisticated, professionalised and successful doping program that sport has ever seen".
Armstrong, who has always denied doping, had previously elected not to contest USADA charges.
Former Armstrong teammates at his US Postal and Discovery Channel outfits, where he won seven successive Tours from 1999 to 2005, testified against him and were given reduced bans by the American authorities.
McQuaid and Verbruggen, who was UCI president when Armstrong won his Tour titles, have been criticised for their handling of the affair.
McQuaid has pledged to do more to clean up the sport but said he would not stand down from his position.
Armstrong's former teammate Tyler Hamilton, whose testimony helped bring down the rider, hit out at McQuaid earlier this week, saying the Irishman had "no place" in the sport.
Hamilton and Floyd Landis, who also testified to USADA, have said the UCI covered up an Armstrong positive test for the banned blood booster EPO at the 2001 Tour de Suisse. The UCI deny this.