Olympic champions Mo Farah, Rafael Nadal and Justin Rose are among the growing list of sports stars to have their medical records released by the hacker group Fancy Bears.
The World Anti-Doping Agency (WADA) says the hackers, who it suspects are based in Russia, broke into its servers on September 12.
The files reveal which athletes have been granted so-called Therapeutic Use Exemptions, which allow the limited use of banned substances on medical grounds.
WADA insists the sporting figures have done nothing wrong, but the hackers say the exemptions are a "doping licence".
Does the international anti-doping system treat all athletes equally?
Presenter: Adrian Finighan
Hajo Seppelt - journalist and filmmaker behind Doping Top Secret: How Russia Makes its Winners
Dr Sergei Iljukov - consultant at the Estonian Anti-Doping Agency
David Larkin - international sports lawyer
Source: Al Jazeera News