Moscow - The Kremlin on Friday rubbished claims of a vast state-run doping programme during the 2014 Winter Olympics in Sochi vaunted as a triumph for Vladimir Putin's Russia.
Kremlin spokesman Dmitry Peskov dismissed the allegations that dozens of Russian athletes including at least 15 medallists took performance-enhancing drugs during the showpiece games when Russia boasted of its efforts to clean up sport.
"These look like absolutely unsubstantiated claims," Peskov told journalists in response to the claims by Grigory Rodchenkov, the former head of Russia's anti-doping laboratory, the latest doping accusations to rock Russian sport.
"It just looks like, you know, let's say, the slander of a defector," Peskov said, using Cold War rhetoric used to refer to Soviet citizens who fled to the West.
Rodchenkov, fearing for his safety and currently living at a secret location in Los Angeles, made the sensational claims to the New York Times on Thursday.
He headed Russia's anti-doping laboratory from 2006 to November 2015 when he resigned after the World Anti-Doping Agency (WADA) accused the laboratory of being part of a state-sponsored doping programme.
In his first interview, Rodchenkov described a massive, tightly-organised doping operation involving Russia's FSB security service and the sports ministry.
"I would not rely on such unsubstantiated claims," Peskov said when asked to comment on alleged involvement by the ministry and the security service.
The claims come as a huge blow to Russia, which spent billions turning Sochi from a rundown resort to a gleaming showcase for the games.
Putin personally backed Russia's bid, even giving an emotional speech in English to the International Olympic Committee.
After dire results at the previous winter games in Vancouver, Russia topped the medals table at Sochi with 13 golds in an apparent turnaround for its sporting fortunes.
"The results show that the difficult period in the history of Russia sport is over," Putin said after the games.
"Everything that was done and invested in our sport has not been in vain," he boasted.
Russia has always insisted that the Sochi games were clean.
WADA in its damning report on Russia last year said that FSB security service officers were present at the anti-doping laboratory in Sochi.
The International Olympic Committee said in November that there was no reason to doubt the anti-doping results in Sochi, however.
WADA has previously focused on Russia's allegedly facilitating drug cheats at the London Olympics in 2012.
Russian sports minister Vitaly Mutko has condemned the latest allegations as "absurd," calling them "a continuation of the information attack on Russian sport".
Kremlin spokesperson Peskov on Friday denied that Mutko risked dismissal.
"No, quite the opposite.... we generally side with his point of view," Peskov said.
Asked if Russian athletes would be able to compete at the Rio Olympics this summer, he said Mutko would need to answer this, but added: "We hope that all will be well."
Russian athletes whose names were on a spreadsheet shown to the New York Times by Rodchenkov, which he said outlined doping plans for Sochi, denied the allegations.
Cross-country skier Alexander Legkov who won gold and silver at Sochi told Sport Express newspaper "I am sure of myself 300 million percent."
"Why should we believe such a person and trust him?" Legkov said of Rodchenkov in a comment in to state television.
Alexander Zubkov, a bobsledder who won two golds, told Sport Express the claims were "complete slander against the athletes of the Russian team and against me as an individual."
"I took part in five Olympics and won medals at three. After each one I took part in doping controls. And now, suddenly someone is trying to pin something on me."
Willi Schneider, the German coach of Russia's skeleton team since 2012 and former Canada coach, told sports website Sportbox.ru that "my personal opinion is all this is dirty politics. There's nothing truthful in these reports, only rumours."
Rodchenkov alleged that skeletonist Alexander Tretyakov, who won gold at Sochi, was among the athletes involved in doping.
Schneider said: "I'm sure Tretyakov was clean."