Chris Froome claimed he was drenched in urine and called a "doper" after enhancing his Tour de France lead on a 14th stage won by fellow Briton Steve Cummings.
Froome (Team Sky) now leads nearest rival Nairo Quintana (Movistar) by three minutes 10 seconds, with his dominance bringing about innuendo and abuse.
The 30-year-old insists he is a clean rider.
He told ITV4: “A spectator threw a cup of urine in my face and said ‘doper’.”
Froome added: “You don’t do that to anyone. It’s not in the name of sport.
“That’s extremely disappointing. Unfortunately I think a lot of the reporting on the race has been very irresponsible.
“What can I do? I can get angry. I’d rather keep my composure and stay focused on the race.”
Team Sky's director of business operations Fran Millar wrote on Twitter: "Froomey's interview saying he had urine thrown in his face by a spectator today. Total and utter disgrace. These people are not fans.
“Repercussions of a minority of people’s baseless and evidence less speculation and innuendo means our riders being punched and urine thrown.
“Watched this race when doped riders got away scott free. Our lads are clean + are facing abuse every day (and yes my brother (David Millar) doped — I know).”
The incident happened on the 178.5-kilometres route from Rodez, which finished at Mende airstrip after the punishing 3km ascent of the Cote de la Croix Neuve.
Froome finished 20th on the stage, four minutes 15 seconds behind Cummings but, significantly, one second ahead of Quintana.
The Colombian climber is now his nearest challenger after Tejay van Garderen (BMC Racing) conceded 40secs to Froome on the stage, falling 3mins 32secs adrift.
The stage was played out through the stunning scenery of the Tarn Valley and stifling heat and with Team Sky’s riders again subject to abuse.
Australian Richie Porte revealed he had been punched by a roadside spectator in the Pyrenees on the ascent to La Pierre-Saint-Martin on Tuesday.
Fans are in such close proximity at the Tour that incidents have happened across the 102 editions of the race. Mark Cavendish alleged he was soaked in urine in 2013.
There has also been threats made on social media towards Team Sky and Froome, although it is difficult to gauge how serious these are.
It is uncertain if any animosity is down to the British squad’s dominance or the unfounded allegations which has resulted from its strong showing in the race so far.
