MOSCOW — Russia on Friday denied that it had operated a state-sponsored doping program at the Winter Olympics in Sochi in 2014, calling the allegations raised by a former lab chief “groundless.”

The accusations were made by Grigory Rodchenkov, the former director of the country’s antidoping laboratory, and were the subject of an article in The New York Times on Thursday.

Dr. Rodchenkov, who said he had fled Russia out of fear for his life, controlled the laboratory that tested thousands of Olympians. He said he had created a special cocktail for Russian athletes and described an elaborate scheme by Russia’s intelligence agency, the F.S.B., to tamper with urine samples in the dead of night in Sochi to avoid detection.

Dmitry S. Peskov, the spokesman for President Vladimir V. Putin, told reporters that the account was not supported by any evidence. “These allegations look absolutely groundless,” Mr. Peskov told Russian news agencies in a conference call. “They are not substantiated by any trustworthy data, they are not backed by any sort of documents. All this simply looks like slander by a turncoat.”