The World Anti-Doping Agency (Wada) has condemned Russian hackers for leaking confidential medical files of US Olympic athletes. Athletes affected include tennis players Venus and Serena Williams and gymnast Simone Biles.
A group calling itself "Fancy Bears" claimed responsibility for the hack of a Wada database. Wada said in a statement that the cyber attacks were an attempt to undermine the global anti-doping system. Russian government spokesman Dmitry Peskov said it was "out of question" that the Kremlin or secret services were involved in the hacking, Russian news agencies reported.