BERLIN (Reuters) - Allegations of Russian doping at the Sochi 2014 Winter Olympics would represent a shocking new dimension and an "unprecedented level of criminality", if proven to be true, International Olympic Committee President Thomas Bach said on Wednesday.
Russia is at the heart of the biggest doping scandal in sport, with its track and field athletes suspended as a result of a probe into accusations of widespread doping and their participation at this year's Rio Olympics in doubt.
Citing the former head of Russia's anti-doping agency, the New York Times reported last week that Russian anti-doping experts and members of the intelligence services secretly broke into tamper-proof bottles to replace urine samples tainted by performance-enhancing drugs with clean urine collected earlier.
"If these allegations are true we will hold everybody responsible who is implicated and there are different kinds of actions that are possible," Bach said in a conference call, citing possible bans or fines for athletes up to entire federations being excluded from the Games.
The Kremlin dismissed the allegations Russia ran a sophisticated doping programme at the 2014 Games at the Russian resort as treacherous slander, calling former agency head Grigory Rodchenkov "a turncoat".
The New York Times report was broadly consistent with accusations of the independent World Anti-Doping Agency (WADA) commission last November of widespread state-sponsored doping in Russia, which led to a ban on the country competing in international athletics competitions.
WADA is now investigating the new allegations over Sochi, while the U.S. Justice Department has opened an investigation into the accusations of state-sponsored doping.
"Should the investigation (into Sochi) prove the allegations true it would represent a shocking new dimension in doping with an, until now, unprecedented level of criminality," Bach said.
"I would like to call on those who may have information to come forward to WADA and to come forward today so as to enable WADA then to come to a result which shows the full picture. We can then make a real judgment to which degree these allegations are true."
Adding to the questions over doping, the IOC said on Wednesday up to 31 athletes could be banned from Rio 2016 following re-tests using newer methods of doping samples from the Beijing Olympics in 2008.
Bach said if any medallist was among those 31 there would not be any automatic reallocation of medals without those athletes also being retested. The names of the 31 athletes are expected to be announced in early June.
The IOC also ordered some 250 retests from London 2012 this week, the results of which are expected within seven days.
The world athletics organisation, the IAAF, meets on June 17 to discuss the participation of Russian track and field athletes in Rio.
Bach said Russian athletes would also possibly need to prove they were clean to compete in Rio.
"The results of the WADA investigation will also greatly influence the nature of the participation of Russian athletes in the Olympic Games Rio 2016," Bach said.
"Should there be evidence of an organised system contaminating other sports, the international federations and the IOC would have to make the difficult decision between collective responsibility and individual justice."
"This could mean that concerned athletes would have to demonstrate that their international and independently proven test record is compliant with the rules of their International Federation and the World Anti-Doping Code," Bach said.
Russia's Sports Ministry said on Wednesday it fully supported actions by the IOC to bar athletes who dope from competitions, but said clean athletes should not be excluded from the Rio Games.
However, the Kremlin said it did not accept the application of U.S. justice outside Washington's jurisdiction.
Reporting by Karolos Grohmann; Editing by Alison Williams