It’s been revealed that US tennis players, Serena and Venus Williams have been allowed by the World Anti-Doping Agency (Wada) to take banned substances.

The revelations were confirmed when a group of Russian hackers named “Fancy Bears” gained access to Wada database on Tuesday and leaked confidential documents.

The documents said that the former No. 1 tennis player Serena Williams was allowed to take banned substances such as oxycodone, hydromorphone, prednisone and methylprednisolone in 2010, 2014 and 2015 while her sister Venus Williams was allowed to take prednisolone and triamcinolone among others in 2010, 2011, 2012 and 2013.