Thomas Bach, the president of the International Olympic Committee, says no organisation is "immune to credibility issues".
Last week, police raided Brazil's Olympic Committee and the home of its president Carlos Nuzman as part of an investigation into an alleged cash-for-votes scheme to secure the 2016 Rio Olympic Games.
Nuzman's lawyer has vehemently denied any wrongdoing, while Bach says the IOC will take strong action if required.
"Credibility for us is extremely important," Bach told a news conference.
"We have taken a series of measures with regard to good governance. We have changed the candidature procedure. New rules and stricter rules have been adopted for the procedure for 2026.
"No organisation in the world is immune. No law is so perfect that it cannot be broken.
"No-one wants to have credibility issues in his or her organisation," added Bach. "But we have to be realistic. No organisation in the world is immune to credibility issues.
"We are following up on everything that has been provided or will be provided by the judicial authorities.
"Once evidence is there, we will act, and we will be in a position to make recommendations in this respect."