LONDON: Tour de France champion Chris Froome has responded to the drug-taking controversy surrounding Bradley Wiggins by claiming sport’s anti-doping rules are open to abuse. Froome took to Twitter to vent about the issues with doping controls after two officially approved Therapeutic Use Exemptions (TUE) earlier in his career were revealed by hackers earlier this month. Froome, who won his third Tour de France title in four years in July, said: “I take my position in sport very seriously and I know that I have to not only abide by the rules, but also go above and beyond that to set a good example both morally and ethically. It is clear that the TUE (therapeutic use exemption) system is open to abuse and I believe that this is something the UCI (cycling’s governing body) and WADA (World Anti-Doping Agency) need to urgently address. Athletes are able to take some banned substances as medication if they are cleared by the authorities and Froome said he has never pushed the boundaries of what is allowed.