Chris Froome insisted his legacy remains unblemished and reiterated his innocence after being asked by the UCI to explain elevated levels of salbutamol in a drugs test at the Vuelta a Espana.
Earlier this year, Froome's maiden Vuelta victory followed his fourth Tour de France triumph, making him just the third man – after Jacques Anquetil and Bernard Hinault – to win the two Grand Tours in the same year.
A urine sample supplied by Froome on September 7, following stage 18 of the Vuelta, showed a concentration of the substance that was double the World Anti-Doping Agency (WADA) threshold of 1,000 nanograms per millilitre (ng/ml).
Asthma medication salbutamol is permitted by WADA rules without the need for a therapeutic use exemption (TUE) when inhaled up to a limit of 1,600 micrograms over 24 hours. The adverse finding, confirmed through a test of the 32-year-old's B sample, does not necessarily constitute a break of the rules and Froome has not been hit with a provisional suspension.
According to Team Sky, the UCI's request for clarification is to "ensure that no more than the permissible doses of salbutamol were inhaled". None of the 20 other urine tests taken by Froome at the Vuelta require further explanation.
"I understand this comes as a big shock to people," Froome told BBC Sport. "I certainly haven't broken any rules here.
"I can understand a lot of people's reactions, especially given the history of the sport. This is not a positive test.
"The sport is coming from a very dark background and I have tried to do everything through my career to show that the sport has turned around."
Asked if he felt his legacy had been tainted by the developments, Froome replied: "No.
"I have been a professional cyclist now, treating my symptoms and racing with asthma, for 10 years.
"I know what those rules are, I know what those limits are and I have never been over those limits.
"I have got a very clear routine when I use my inhaler and how many times. I have given all that information to the UCI to help get to the bottom of it."