LONDON — The latest allegations of state-sponsored doping in Russia could lead to suspension of entire national federations, heavy fines and lifetime Olympic bans, IOC President Thomas Bach said Wednesday.

Bach declined to say whether the IOC would consider banning Russia entirely from this year's Olympics in Rio de Janeiro, maintaining such a move hinges on a choice between "collective responsibility" and "individual justice."

"We are waiting for the facts," Bach said. "We need a fair procedure for everybody. Should the allegations be proven true, we will apply our zero tolerance policy, not only with the athletes, but also with regards to everyone implicated within our reach."

Bach also said the final results of retests of doping samples from the 2008 and 2012 Games — which have caught 31 athletes so far — will be known early next month, in time for drug cheats to be barred from going to the Olympics in Rio de Janeiro in August.

Bach said allegations that Russian officials subverted the drug-testing system at the 2014 Winter Games in Sochi "represent a shocking new dimension in doping" and an "unimaginable level of criminality."

Grigory Rodchenkov, the former head of the Russian lab now living in Los Angeles, told The New York Times last week that he ran an organized doping program for Russian athletes and helped switch tainted samples for clean ones. Rodchenkov said he was helped by people he believed to be Russian security officers.

The IOC has asked the World Anti-Doping Agency to carry out a full-fledged investigation and plans to retest Sochi samples stored at the lab in Lausanne, Switzerland. Bach urged anyone with information about the allegations to come forward immediately to WADA and the IOC.

"If these allegations are true, we will hold everybody responsible who is implicated," Bach said in a conference call with reporters.

He said sanctions could include lifetime Olympic bans on individuals, financial penalties on organizations and "suspensions or exclusion of entire national federations" — in line with the IAAF's current suspension of the Russia's track and field body.

The IAAF suspended Russia from global competition following an investigation by an independent WADA panel that detailed state-sponsored doping, corruption and coverups in the country's track and field program.

The IAAF is scheduled to decide on June 17 whether to maintain or lift the ban on the Russians for the Rio Games.

Bach was asked whether, in light of the Sochi allegations, the entire Russian Olympic Committee could be banned from Rio.

"I will not speculate on the result because there comes a decision we have to make between collective responsibility and individual justice," he said.

The IOC would have to consider "whether in such contaminated federations the presumption of innocence for athletes could still be applied, whether the burden of proof could be reversed," he added.

Bach said decisions also have to be made taking into account "the clean athletes around the globe."

"Whatever the results will be, we will do everything to provide a level playing field for all the athletes around the globe and in this way to protect the integrity of the competition of the Olympic Games in Rio," he said.

The Russian sports ministry said Wednesday it supports banning drug cheats but claimed it would be unfair to keep a blanket ban on all track athletes for the games.

"We strongly believe that clean athletes, who have spent years of their lives training for the games, should not be deprived of the right to participate," the ministry said.

Russian Sports Minister Vitaly Mutko told the state news agency Tass that Russia was prepared to appoint a foreigner to head its anti-doping agency.

Bach said he had no knowledge of a reported investigation by U.S. federal prosecutors into allegations of state-sponsored doping of Russian athletes. The probe was launched by the U.S. Attorney's office for the Eastern District of New York, The New York Times reported.

"We have no information on this," Bach said. "I don't even know what it is. I don't know about any legal grounds for this. I don't know about the scope. I cannot comment on something I do not know."

Mutko said Russia was surprised by the reported U.S. investigation and suggested the United States should investigate its own national team, because "things are not so rosy there either."

Bach spoke a day after the IOC announced that 31 unidentified athletes in six sports could be barred from Rio after their Beijing doping samples tested positive. The IOC stores samples for 10 years to allow for retesting with improved techniques.

IOC medical director Dr. Richard Budgett said the athletes' "B'' samples will be analyzed in early June and the results available a few days later.

The IOC has also retested 250 samples from the 2012 London Olympics. Budgett said provisional results from those tests will be available within a week, with testing of the "B'' samples to take place "a couple of weeks later."

Budgett said athletes will be invited to be present for the testing of the "B'' samples. If those tests also come back positive, the IOC can issue provisional suspensions. That would be followed by a disciplinary procedure that could bar athletes from Rio and strip them of their previous Olympic results, including any medals.

Budgett declined to say which substances were detected in the retests, but said the process involved improved methods for detecting steroids and EPO.

Budgett added that a test for gene doping developed by Australian scientists was in the final stages of approval and could be ready for use at the Rio Games.