Three-time Tour de France winner Greg LeMond has urged Pat McQuaid to quit as head of world cycling's governing body the UCI in the wake of the Lance Armstrong doping affair.
LeMond, who won the Tour in 1986, 1989 and 1990, says McQuaid and his predecessor as UCI chief, Hein Verbruggen, have destroyed the sport.
On his Facebook page LeMond says McQuaid knows what has been going on so it's time to walk away if he loves cycling.
Earlier this week McQuaid warned against blaming the sport's authorities for doping scandals after Armstrong was banned for life and stripped of his seven Tour de France wins.
Verbruggen has come under scrutiny for his role in the Armstrong affair as he was at the helm at the time of the shamed US rider's consecutive wins in cycling's most gruelling race between 1999 and 2005.
In particular, Verbruggen has been accused of shielding the Texan amid claims he and US Postal Service team-mates were tipped off about the arrival of dope testers and the UCI received a donation from Armstrong allegedly to cover up a positive test, but Verbruggen has denied the claims.