Chris Froome has asked why his performance in leading the Tour de France has invited more scrutiny than any of his rivals’ displays in winning other major races.

Froome (Team Sky) leads by three minutes 10 seconds from Nairo Quintana (Movistar) with five stages remaining, four of them in the Alps where the yellow jersey will be won.

Yesterday was a rest day and the race finishes in Paris on Sunday.

The 2013 champion was part of the ‘big four’ entering the race, but defending champion Vincenzo Nibali (Astana) and Alberto Contador (Tinkoff-Saxo) have endured challenging races and Quintana, runner-up to Froome two years ago, is expected to find his best form in the Alps.

Froome has been subjected to innuendo and interrogations over his dominant win to La Pierre-Saint-Martin on stage 10, when Team Sky colleague Richie Porte was second, 59 seconds behind, and Quintana third, 1min 04secs adrift, as Giro winner Contador and, in particular, Nibali struggled.

Rather than assess his rivals’ under-par showings, Froome’s detractors have focused on his display with some concluding he must be doping.

He insists he races clean.

“I’ve got to admit it is frustrating to an extent that if you look at the last five Grand Tours that have been won by different riders, there hasn’t been the same kind of outcry for power data and numbers and all the rest of it,” Froome said.

“Unless I’m missing something. I didn’t see the same kind of level of questioning.

“Of course, I don’t really understand why now it seems to be such a hot topic in this year’s Tour de France, given that, okay I won one mountain top finish by 59 seconds. It just seems strange to me.”

Host broadcaster France 2 on Sunday broadcast an expert analysing Froome’s ascent in the first Pyrenees stage, with Pierre Sallet concluding his power profile of 7.04 watts per kilogramme was “abnormally high”.