The International Olympic Committee (IOC) says a damning report exposing Russia's state-run doping shows "a shocking and unprecedented attack on the integrity of sport and on the Olympic Games".
In a statement, IOC president Thomas Bach said "the IOC will not hesitate to take the toughest sanctions available against any individual or organisation implicated".
The IOC executive board will meet tomorrow to make its first decisions, which could include sanctions against Russia for the upcoming Rio Games.
The World Anti-Doping Agency (WADA) report has found systematic, state-controlled doping in Russia benefited athletes across a range of sports over at least a four-year period.
The investigation by Canadian law professor Richard McLaren uncovered a system of cheating in which samples were tampered with and positive tests turned into negative results at Russian laboratories.
Prof McLaren's report says the doping was "a state-directed method following the very abysmal medal count by the Russian Olympic athletes participating in the 2010 Winter Olympic Games in Vancouver".
The report found there was a comprehensive cover-up of doping by Russian athletes ahead of the 2012 Olympics in London, as well as the Sochi Winter Olympics and other world championship events.
The IOC is now being urged to ban Russia from the Olympics altogether.
Prof McLaren was appointed in May to investigate the allegations made by the former director of the Moscow laboratory, Dr Grigory Rodchenkov.