Evidence of widespread state-sponsored doping by Russian athletes at the Sochi Olympics has been confirmed in a report by an independent commission of the World Anti-Doping Agency.
The International Olympic Committee says the doping cover-ups confirmed by the World Anti-Doping Agency (WADA) showed a "shocking and unprecedented attack on the integrity of sport and the Olympic Games", and that it would not hesitate to take the toughest sanctions.
An independent report commissioned by WADA confirmed systematic abuse of the anti-doping process across many sports by Russian authorities before and during the Winter Olympics in the Russian city of Sochi in 2014.
According to the report, which was led by Canadian law professor and sports lawyer Richard McLaren and was unveiled at a Toronto news conference, a Moscow laboratory protected Russian athletes' during the 2014 Sochi Winter Games.
Mr McLaren, who was a member of WADA's independent commission which last year exposed widespread doping and corruption in Russian athletics, said the Russian Ministry of Sport oversaw the manipulation of athletes' analytical results and sample swapping.
WADA made seven recommendations after the report was published, including one that Russian government officials be denied access to international competitions, including Rio 2016.
Among the other recommendations, WADA said international federations from sports implicated in the report consider action against Russian national bodies and that Mr McLaren and his team complete their mandate provided WADA can secure funding.
In a statement, IOC President Thomas Bach said the IOC "will now carefully study the complex and detailed allegations in particular with regard to the Russian Ministry of Sport".
"The findings of the report show a shocking and unprecedented attack on the integrity of sports and on the Olympic Games," he said. "Therefore, the IOC will not hesitate to take the toughest sanctions available against any individual or organisation implicated."
The IOC Executive Board will hold a telephone conference tonight to take its first decisions, which could include provisional measures and sanctions regarding the Olympic Games in Rio de Janeiro next month, the IOC said.
Last week, Mr Bach indicated a total ban on Russia competing in Rio was unlikely, saying: "It is obvious you cannot sanction a badminton player for an infringement of the rules by an official or a lab director at the Winter Games."
However, in the light of the report, with a wide group of sports bodies now calling for a blanket ban, a broad sanction could now be on the cards.
Russia's track and field athletes are already banned, as are its weightlifters, subject to confirmation of positive dope tests from samples given in 2008 and 2012.