Rafael Nadal's confidential World Anti-Doping Agency records are among the latest that were leaked by an alleged Russian hacker group.
Serena and Venus Williams, Petra Kvitova and Bethanie Mattek-Sands previously had their records released.
A total of 26 athletes had their records published in this round of leaks.
It shows two Therapeutic Use Exemptions (TUEs) given to Nadal. The Spaniard was given approval for betamethasone, a corticosteroid used for reducing inflammation, in 2009 following the U.S. Open.
RAFA NADAL fue autorizado a tomar Betametasona y Corticotropina por la Agencia Mundial Antidopaje y la Fed Int Tenis pic.twitter.com/u2NmaNwL38— El Partidazo de COPE (@partidazocope) September 19, 2016
He was also approved for the use of corticotrophins in 2012, during the period in which he was sidelined from the tour with another knee injury. The TUE was required because corticotrophins are prohibited for use even when athletes are not competing.
Nadal, speaking to Spanish reporters, confirmed that the documents were authentic, and said he was authorized by anti-doping officials to take the substances during those time periods.
"There are many things which, day to day, are banned substances,” he said, “but when you ask permission and you get it, it stops being illegal … I have never taken anything to improve my sporting performance. Simply, the doctors [told] me to take something to improve my knee.”
Nadal has previously called for his tests to be made public, and is in the process of suing a former French government minister who alleged that he received “silent bans” for doping. Currently, there is only an announcement if an athlete tests positive.
"It is a private matter which does not need to be private," he said. "No need for a hacker to deliver it. It would be good for everyone. If every time you successfully do a doping test, [and] it's announced and the results are published, it would finish all these discussions and all be transparent."
The ATP also issued a statement in regard to the leaks.
Statement from ATP Executive Chairman & President Chris Kermode regarding the hacking of WADA athlete files: pic.twitter.com/LhXIWdCjXq— ATP World Tour (@ATPWorldTour) September 19, 2016
A TUE gives an athlete permission to use an otherwise banned substance for a specific period for a specific medical reason. In tennis, it is approved by the International Tennis Federation following submission to a group of medical experts who do not know the identity of the athlete.
After the first attack, WADA confirmed that its databases were the subject of a security breach, which it described as "retaliation" for an investigation into state-sponsored doping in Russia.