Bach was on defense throughout a news conference held after a meeting of the IOC executive board, which earlier in the day said it was asking Brazilian authorities for details involving IOC member Carlos Nuzman.
Nuzman, the organizer of the Rio Games, is accused of funneling USD 2 million to another former IOC member, Lamine Diack, to secure votes to bring the 2016 Olympics to Rio de Janeiro.
"We have taken action in the case of Mr. Diack," Bach said, in reference to the former head of track and field whose IOC membership has been stripped. "When evidence is provided (in the Nuzman case), we will act. But in order to take action, you need evidence."
Less than two years ago, Bach was critical of FIFA, which was embroiled in a bidding scandal of its own. He urged soccer's governing body to get its house in order because it could "continue to overshadow the credibility of FIFA and affect all sports organizations for such a long time."
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"Nobody wants to have credibility issues," Bach said. "But we have to be realistic. No organization in the world is immune to credibility issues. We have to face this reality and we have undertaken the reforms and provided ourselves with the instruments to tackle these challenges. I hope these will also be respected."
Fredericks has denied wrongdoing, saying a USD 300,000 payment he received from Diack's son on the day Rio won the vote for 2016 was for legitimate consultancy work.
Bach also parried questions about doping. The IOC is still awaiting conclusions from a pair of committees before determining the fate of Russian athletes for next year's Winter Games. The committees are studying evidence from the McLaren report , which documented widespread doping fraud inside the country at the Sochi Games and beforehand.
And yet, the IOC's handling of the doping issue was a mere subplot to the issue of whether the organization's bidding process is irreversibly broken.
Because neither 2024 nor 2028 will be subject to a competitive vote, Bach likely has avoided that issue for the time being. He called getting Paris and Los Angeles on the Olympic calendar a "golden opportunity" that the IOC simply couldn't pass up. And yet, that led to questions about whether the change in strategy was nothing more than a quick fix to remove the voting power from the 94 IOC members' hands.
But all the questions Monday circled back to one simple theme: Does the IOC have an image problem?
"This is not my call to speak of the IOC's image, because it's in the eyes of everybody," Bach said. "Everybody should make their own judgment. The only hope I have is that the judgment is made on facts and actions, and not so much by perceptions.