LONDON: World athletics chief Sebastian Coe has defended the system of “therapeutic use exemptions” (TUEs) after medical data involving dozens of top sportsmen was leaked by a cyber hacking group. Many of the targeted athletes have been revealed to have received TUEs for the use of substances that would usually be on the World Anti-Doping Agency (WADA) banned list. TUEs can be issued to athletes who have an illness or condition that requires the use of normally prohibited medication. Among those with a history of TUE use who have had their medical details leaked as a result of a hack into the WADA system by cyber group Fancy Bears, which is believed to be based in Russia, are American tennis stars stars Serena and Venus Williams, American gymnast Simone Biles and British Tour de France-winning cyclists Bradley Wiggins and Chris Froome. There is no suggestion that any of the named athletes have done anything wrong.