The International Olympic Committee (IOC) has launched disciplinary proceedings against 28 Russian athletes from the 2014 Sochi Winter Olympics.
The moved Friday follows the findings of the second McLaren report on doping at the beginning of the month.
As a result of the IOC action, the international ski federation FIS said it was imposing provisional bans to six unnamed Russian cross-country skiers.
Canadian lawyer Richard McLaren, appointed by the World Anti-Doping Agency (WADA) as independent investigator, said evidence of manipulation of samples was shown in the cases of 28 athletes.
McLaren said more than 1,000 athletes were implicated in what his report described as a Russian programme of state-sponsored doping.
Russian President Vladimir Putin Friday acknowledged his country had a problem with athletes using performance-enhancing drugs, but said Russia has "never had any state system supporting doping."
Russia is working closely with the IOC and WADA in an effort to combat its problem with doping, he said.
The IOC said of the 28 Russian athletes under investigation that there was "evidence of manipulation of one or more of their urine samples" from the Sochi Games.
McLaren had investigated 95 samples of Russian athletes the IOC had provided to him, it said.
"They led to the 28 athletes with evidence of sample manipulation. They have now been repatriated back to the Lausanne Anti-Doping Laboratory, and re-analysis has already begun on these samples looking for any Adverse Analytical Findings (AAFs)," a statement said.
IOC president Thomas Bach said the IOC would "go beyond the findings" of McLaren by re-analysing all the samples of all Russian athletes who participated in Sochi and the 2012 Olympics.
The 28 Sochi cases are not comparable to a positive doping control, the IOC said. However sample manipulation could lead to a doping rules violation and sanctions.
Twenty-seven Russian athletes have already been sanctioned by the IOC as a result of its own re-analysis programme for the 2008 Beijing Games and London 2012, which is continuing for London, the IOC said.
The IOC will also re-analyse all samples from Russian athletes at the 2010 Winter Games in Vancouver.
FIS said its provisional ban on six Russian cross-country skiers was effective from December 22.
A statement said it was "not empowered to communicate the names of the athletes before the disciplinary proceedings are concluded in accordance with the provisions of the World Anti-Doping Code, and leaves it to the athletes and the Russian Ski Association to do so."
FIS president Gian Franco Kasper said the findings in the McLaren report "have seriously damaged the integrity of sport and we are determined to ensure the necessary measures are undertaken to punish the offences."
FIS will work with the Russian ski federation "to rehabilitate the Russian cross-country skiing community and we sincerely count on their commitment to clean sport," he added.
The doping investigations have led to a number of winter sports events being moved from Russia.
The end-of-season World Cup finals of the speed skaters in Chelyabinsk and the cross-country skiers in Tyumen, both in March, will be relocated to another country.
Earlier this month the bobsleigh and skeleton world championships were relocated from Sochi to Koenigssee, Germany.
On Thursday, the Russian Biathlon Union voluntarily returned the junior World Cup in Ostrov and a World Cup event in Tyumen. A new venue will be announced at a later date.
Two Russian biathletes have been provisionally suspended and 29 others have been put under investigation, the International Biathlon Union (IBU) said Thursday.