Hacking group Fancy Bear leaked WADA documents showing that the agency allowed US tennis players Serena and Venus Williams, as well as Olympic gold-winning gymnast Simone Biles, to take banned substances.
Serena and Venus Williams were allowed to take prednisone for example. Simone Biles, who won four gold medals in the 2016 Olympics in Rio, tested positive for methylphenidate (Ritalin) in August, but was allowed to compete despite the obvious advantage this gave her.