Antidoping regulators and the I.O.C. have conducted their own investigations of Dr. Rodchenkov’s claims and Russia’s actions. After both inquiries confirmed his account, citing the accounts of other anonymous witnesses as well as forensic evidence, Russia was barred from taking part in the upcoming Winter Games in Pyeongchang, South Korea.
Russian officials have vehemently denied the Sochi cheating scheme described by Dr. Rodchenkov as well as the existence of a state-sponsored doping program. Russian President Vladimir V. Putin said that Dr. Rodchenkov’s actions “are controlled by the US intelligence services.”
“What drugs are they giving him to make him say what they want him to say?” Mr. Putin wondered during his annual news conference in December. “This is just ridiculous.”
Dr. Rodchenkov is currently living in the United States under protection from American authorities and is believed to be a target of Russian special agents. Two criminal cases were opened against Dr. Rodchenkov in Russia and a court arrested him in absentia.
Russian investigators claimed that he distributed doping materials among athletes and made claims about a state-sponsored doping program in Russia in order to avoid responsibility for his drug distribution.
Russian investigators in Moscow have said they questioned more than 700 Russian athletes, coaches, and medical workers about Dr. Rodchenkov’s claims but that no one confirmed them, and that staff members of the Sochi Olympic antidoping center have testified that samples were not swapped.
The lab had a staff of nearly 100 people, including employees of Dr. Rodchenkov’s lab in Moscow as well as dozens of international antidoping experts from around the world. Officials from the I.O.C. and the World Anti-Doping Agency have emphasized their conclusions were “not only based on the witness evidence provided by Dr. Rodchenkov,” but also on “forensic and analytical studies, which corroborated the implementation of the alleged scheme.”
In an earlier statement, Russian investigators said that some Russian athletes and coaches admitted that Dr. Rodchenkov distributed substances “whose authentic qualities were not known to them” but that later “appeared to be doping.”
Russian investigators also said that they could not find a hole in the wall of the antidoping lab, through which Dr. Rodchenkov said tainted urine samples were passed in Sochi, across the security perimeter of the lab. They also claimed that higher-than-usual amounts of salt in the doping samples of Russian athletes are connected “with the peculiarities of physiological metabolism processes in peoples’ kidneys after physical activity as well as with the volume and contents of consumed liquids.”
Dr. Rodchenkov said earlier that he had added salt or water to clean samples to balance out any inconsistencies in pre-recorded chemical specifications. An investigator for the World Anti-Doping Agency concluded that the urine samples in question had “physiologically impossible salt readings.”