Hackers have published confidential medical data belonging to a handful of high-profile American athletes including Serena Williams and Simone Biles.
WADA identified the hackers as a Russian group known as Fancy Bear, which published what are called therapeutic use exemptions, waivers that allow athletes to take banned substances on medical grounds.
The data for the Americans, which also included Venus Williams and basketball player Elena Delle Donne, was posted online Tuesday, with threats that more files would follow. Fancy Bear claimed on its website that the leaked documents prove the athletes had broken anti-doping rules.
The International Olympic Committee and the U.S. Anti-Doping Agency said the documents proved the opposite.
“In fact, in each of the situations, the athlete has done everything right in adhering to the global rules for obtaining permission to use a needed medication," USADA Chief Executive Officer Travis Tygart said in a statement. “The cyber-bullying of innocent athletes being engaged in by these hackers is cowardly and despicable.”
The IOC also condemned the attack, and confirmed that the athletes mentioned didn’t break anti-doping rules during the 2016 Olympics.
Biles, who won four gold medals in Rio, wrote on Twitter that she has taken medicine for Attention Deficit-Hyperactivity Disorder (ADHD) for years. “I believe in clean sport, have always followed the rules, and will continue to do so as fair play is critical to sport and is very important to me.”
In her next post, she continued, “Having ADHD and taking medicine for it is nothing to be ashamed of, nothing that I’m afraid to let people know.”
Delle Donne also responded on social media. “I’d like to thank the hackers for making the world aware that I legally take a prescription for a condition I’ve been diagnosed with, which WADA granted me an exemption for,” she wrote in posts on Facebook and Instagram.
Representatives for the Williams sisters didn’t respond to requests for comment.
The group of hackers targeted WADA earlier this year, releasing information about Russian athlete Yuliya Stepanova. Stepanova had earlier given evidence that supported allegations of a program of widespread doping in Russian sport.
Russia’s track and field team was banned from the 2016 Rio de Janeiro Olympics. The country’s President Vladimir Putin denied that the state had any role in the doping scandal, saying that claims to the contrary were politically motivated.
"WADA condemns these ongoing cyber-attacks that are being carried out in an attempt to undermine WADA and the global anti-doping system," director general, Olivier Niggli, said in a statement. "WADA has been informed by law enforcement authorities that these attacks are originating out of Russia."
Russia remains suspended from track and field until its anti-doping procedures are fit for purpose. The IOC had taken a less severe view than track and field, allowing athletes from Russia to perform at Rio 2016 providing they could be cleared by the relevant sports governing body. IOC President Thomas Bach had said a blanket ban would’ve been disproportionate.
"The cynical ‘collateral damage approach’ is not what the Olympic movement stands for," Bach said before the games.