MOSCOW: Twenty-eight Russian athletes who took part in the 2014 Winter Olympics in Sochi face disciplinary proceedings over possible manipulation of their urine samples, the International Olympic Committee (IOC) said on Friday.

The global skiing body (FIS) later announced that it had suspended six Russian cross-country skiers who were among those being investigated and said Russia had pulled out of hosting the final meeting of the sport's World Cup season.

The moves follow publication earlier this month of the second and final part of the World Anti-Doping Agency's independent McLaren report into Russian doping.

It found more than 1,000 Russian competitors in more than 30 sports were involved in an institutional conspiracy to conceal positive drug tests over the course of five years.

The IOC said on Friday that in the case of the 28 athletes being investigated, there was "evidence of manipulation of one or more of their urine samples" collected at the 2014 Sochi Games for doping tests.

The IOC added that the 28 cases were not considered positive doping tests although "the manipulation of the samples themselves could lead to an Anti-Doping Rule Violation and sanctions." IOC president Thomas Bach said: “This is the immediate follow-up to Professor (Richard) McLaren’s Report.

"The IOC will go beyond the findings of the (McLaren) report by re-analysing all the samples of all the Russian athletes who participated in the Olympic Winter Games Sochi 2014 as well as all those who participated in the Olympic Games London 2012.”

SYSTEMATIC COVER-UP

The McLaren report said there was a systematic cover-up, which was refined at the 2012 Olympics, 2013 world athletics championships and 2014 Sochi Winter Olympics.

It said that more than 30 sports were involved in concealing positive doping samples.

Among its findings the report said four Sochi gold medallists had samples with physiologically impossible salt readings, while there was evidence that bottles containing the urine samples of 12 Russian Sochi medallists had been tampered with.

Russian President Vladimir Putin said on Friday there were some problems with sports doping in Russia, but that there was no state-sponsored doping system as critics have alleged.

Speaking at an annual end-of-year news conference, Putin said that sports should not be politicised.

The FIS said Russia had "returned" the final meeting of the cross-country World Cup season, due to be held in March in Tyumen, as a sign of goodwill.

"The Russian Cross-Country Ski Association has communicated to FIS their determination to build its credibility in the cross-country skiing community and commitment to clean sport," said the FIS.

FIS president Gian Franco Kaspar said the McLaren report's findings had "seriously damaged the integrity of sport and we are determined to ensure the necessary measures are undertaken to punish the offences.

"We will work together with the Russian Ski Association to rehabilitate the Russian cross-country skiing community and we sincerely count on their commitment to clean sport."

Russia has already been stripped of the right to host next year's bobsleigh world championships in Sochi in March and a speed skating event scheduled for Chelyabinsk in the same month by the governing bodies of the respective sports.

It has also pulled out of hosting a World Cup biathlon meeting in Tyumen, due to be held the week before the cross-country event.