MOSCOW, September 13. /TASS/. The International Olympic Committee (IOC) confirmed in its statement for TASS that the global Anti-Doping Administration & Management System (ADAMS) has been recently hacked.

Fancybear.net web portal of hackers announced earlier that it hacked the ADAMS and leaked documents proving that the World Anti-Doping Agency (WADA) allowed US tennis stars Serena and Venus Willams as well as US four-time Olympic Champion in gymnastics Simone Biles taking banned performance enhancing drugs.

"We cannot comment on documents that have been illegally obtained from the ADAMS system," the IOC told TASS. "The IOC strongly condemns such methods which clearly aim at tarnishing the reputation of clean athletes."

The International Gymnastics Federation (FIG) refused to make comments on the issue to TASS.

The IOC denied in a statement to TASS on Tuesday that a group of titled US athletes took banned performance enhancing drugs as it was alleged earlier.

"The IOC strongly condemns such methods which clearly aim at tarnishing the reputation of clean athletes," the statement from the IOC said. "The IOC can confirm however that the athletes mentioned did not violate any anti-doping rules during the Olympic Games Rio 2016."