Tennis star Rafael Nadal is the latest victim of a group of Russian hackers leaking confidential medical records of famous athletes. On Monday, leaked records showed Nadal’s history with the use of banned substances.

The records of the World Anti-Doping Agency (WADA) has been accessed by a group who calls themselves Fancy Bears. The files of interest are the Therapeutic Use Exemption (TUE) obtained by Olympic athletes. The TUE is applied for when an athlete undergoes medication for a proven medical condition which is to be treated by a substance banned by WADA.

The Fancy Bears have been speculated to have a connection with the Russian government. While those claims have so far been denied, the motivation between the hacks has been connected to the recent controversy surrounding Russian athletes who were banned from the 2016 Rio Olympics.

The difference between the use of these substances as a performance enhancement drug and as a treatment for an injury or similar medical conditions is a responsibility that lies with WADA. According to the leaked records, Rafael Nadal was revealed to have been granted a TUE in 2009 and 2012. Those who follow Nadal’s career would know that he went on an extended injury break in 2012.

The extended break continues to haunt Nadal after speculations surfaced about the real reasons behind it. The New Daily recounts how French politician Roselyne Bachelot publicly claimed that the injury break was a cover up after Nadal allegedly tested positive for a banned substance. Nadal has since filed a lawsuit against Bachelot.

Earlier this year, fellow Tennis ace Maria Sharapova was hit with a two-year ban after testing positive for meldonium at the Australian Open. She admits to have been prescribed the drug for a medical condition since 2007. She also claims to have been unaware that the drug has been declared a banned substance since Jan. 1, 2016.