Chris Froome: Tour de France leader 'sad' at doping questions Tour de France leader Chris Froome of Team Sky has admitted his frustration at constant questions about doping. Froome extended his advantage with a stunning ride on Sunday but faced more doping questions on Monday's rest day. I've also believed in people who have turned out to be cheats and liars but I can assure you I'm not Chris Froome Tour de France leader He said: "It's sad that we're sitting here the day after the biggest victory of my life talking about doping." And Sky boss Sir Dave Brailsford said he is prepared to give the World Anti-Doping Agency (Wada) all his team's data in an attempt to allay suspicions. Kenya-born Briton Froome, 28, increased his lead to four minutes 14 seconds in winning Stage 15 on Mont Ventoux on Sunday but his success has not been universally acclaimed, despite Froome and Brailsford insisting that Sky are riding clean. Froome said on Monday: "My team-mates and I have been away from home for months training together and working hard to get here, we've slept on volcanoes to get ready for this, and here I am accused of being a cheat and a liar. That's not cool. On Sunday the sport of athletics was shaken by news that sprinters Tyson Gay and Asafa Powell had both failed drugs tests. And in light of Lance Armstrong's admission earlier this year that he used performance-enhancing substances throughout his seven successive Tour de France victories from 1999 to 2005, there has been renewed questioning of riders during the Tour. Speaking following his Mont Ventoux success, Froome sought to distance himself from any comparisons with Armstrong. "Lance cheated," he said. I'm not cheating. End of story. Some of the sceptics want Sky to release the output data of their riders, but Brailsford does not want to release their 'trade secrets' to rival teams. However, he suggested anti-doping organisation Wada could be given full access to all the team's information. "They can have everything we've got," he said. They can come and live with us. They can see all of our data, have access to every single training file we've got. They can then compare that data on a consistent basis. And they could then tell the world whether they think this is credible or not. Froome told BBC Sport: "I can understand why people are asking [about doping], given the history of the sport - they have been let down so many times before. But I'm also one of those people who's been let down. I've also believed in people who have turned out to be cheats and liars. But I can assure you, I'm not.