International Olympic Committee not immune to credibility issues - Thomas Bach
No organisation is "immune to credibility issues", according to International Olympic Committee president Thomas Bach.
Police last week raided Brazil's Olympic committee and its president's home as part of investigations into what police say is "strong evidence" of vote-buying to secure Rio's bid.
Bach said action would be taken if allegations are proven.
"Credibility for us is extremely important," said Bach.
"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."
Bach said lawyers for the IOC's ethics commission had contacted Brazilian authorities hoping to obtain further details about Carlos Nuzman's case, after the head of the Brazilian Olympic Committee was questioned and had his passport seized.
The 72-year-old is accused of acting as an intermediary in a cash-for-votes scheme to ensure the support of influential IOC member Lamine Diack, who was also serving as president of the International Association of Athletic Federations (IAAF) at the time.
Diack was arrested in Paris in 2015 for corruption allegations involving the covering up of the Russian doping scandal.
Nuzman's lawyer told journalists his client had "done nothing wrong".
"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."
Bach was also asked if he had watched Icarus, a documentary about state-sponsored Russian doping, and admitted he had not.
The film includes details of how one of the biggest scandals in Olympic history was alleged to have taken place at the Sochi Winter Olympics.
'No plan B for Winter Olympics'
Bach said he was confident there would be no threat to the 2018 Winter Olympic Games, which take place in Pyeongchang, South Korea, from 9-25 February.
Pyeongchang is 50 miles from the border with North Korea, which has been hit with United Nations sanctions following its sixth nuclear test.
Lee Hee-Beom, president of the 2018 Winter Games organising committee, added: "There's no plan B, as the Olympics are based on an Olympic truce."
Meanwhile, the IOC, Olympic Solidarity and Pan-American Sports Organisation have set up an emergency fund of $1m (£760,000) to help support Caribbean countries affected by Hurricane Irma.
The money will be used to rebuild sport infrastructure.