Dr. Grigory Rodchenkov, director of Russia’s anti-doping laboratory, has fled to the United States to seek protection after blowing the whistle on a government-sponsored doping campaign that helped Russia win 33 medals at the Olympic Games in Sochi, two years ago. The operation, which was outlined by The New York Times, involved Rodchenkov, a number of Russian anti-doping experts and members of the Russian intelligence service replacing supposedly tamper-proof, drug-positive urine samples with clean urine. Rodchenkov also claims to have developed a mixture of three banned substances combined with alcohol, which he gave to a number Russian athletes, including two gold-medal-winning bobsledders.

Russian sport has long been tainted by doping allegations. At the 2012 Olympics in London, a WADA report also alleged a widespread government-sponsored doping problem in Russia. The country’s main professional cycling team, Katusha, has also been known for extensive use of banned substances.

Some Olympic athletes are tired of feeling cheated. American bobsledder Steven Holcomb said to The New York Times that he doesn’t “feel comfortable going to [his] next Olympic Games knowing that the Russians will be there because they’ve cheated like this. I say, ban them from the sport and the Olympics completely until they can prove that they’ve cleaned up their act and prove that they can be on a level playing field.”

The IAAF provisionally banned Russia from all international competition late last year, which includes the 2016 Olympics in Rio, but the IAAF only includes sports like track and field. Currently, Russia is permitted to partake in other Olympic competitions. However, the International Olympic Committee is launching a full investigation into the allegations, which could result in Russia being completely banned from the 2016 games and future competitions as well.