The International Olympic Committee (IOC) has promised to cooperate with Brazilian authorities in the ticket scalping investigation that has targeted one of its executive board members.
The statement came as IOC president Thomas Bach missed the opening of the Paralympics in Rio de Janeiro, where police wanted to interview him about the case.
Patrick Hickey, president of Ireland's national Olympic committee, was among 10 people charged by Brazilian prosecutors on Tuesday with ticket scalping, conspiracy and ambush marketing in a case that broke during last month's Rio Games.
Police investigator Aloysio Falcao said authorities want to speak with Mr Bach about email exchanges between him and Hickey related to ticket allocations to Ireland.
Mr Falcao said police had planned to "summon" Mr Bach when he came to Rio for Wednesday's opening ceremony of the Paralympics, adding that authorities have no evidence that he knew of the alleged ticket scam.
Mr Bach cancelled plans to attend the opening. The IOC said he would be in Germany instead for the official state mourning ceremony for former West German President Walter Scheel, who died last month at the age of 97.
It is the first time an IOC president has missed the opening of a Paralympics since they were held in conjunction with the Summer Olympics in 1988.
The Brazilian newspaper Globo said Bach would be subpoenaed as a witness if he came to Brazil.
"The IOC cannot comment on a newspaper story nor on the ongoing legal procedure against Hickey for whom the presumption of innocence prevails," the IOC said in a statement to The Associated Press. "For the IOC it goes without saying that it will cooperate on this matter."
It is unclear if Mr Bach will go to Brazil for any of the Paralympics, which last until September 18.
Hickey went to police headquarters in Rio on Tuesday, but declined to answer additional questions.
"We found enough evidence linking Hickey to this plot to sell tickets by a company that was not authorised," prosecutor Marcos Kac told The Associated Press. "These are tickets that were sold for up to 8,000 dollars."
The 71-year-old Hickey was arrested on August 17 during the Olympics in a dawn raid on his Rio hotel room. After a two-day stay in a local hospital to undergo tests, he was held in a high-security prison complex.
Hickey was freed last week when a judge ruled that he was not a risk to the public or the investigation. His passport was confiscated, and he must remain in Brazil until the case is concluded.
Hickey has temporality "stepped aside" from all his Olympic roles - IOC member, IOC executive board representative, Olympic Council of Ireland president, head of the European Olympic Committees and vice president of the Association of National Olympic Committees.
Police have said that Hickey plotted with businessmen to transfer tickets illegally from a sports company called Pro 10 to hospitality provider THG Sports, which was a non-authorised vendor and allegedly sold them for very high fees. Police investigators said the scheme was planned to bring in three million dollars.
The head of THG Sports, Kevin James Mallon, was arrested on August 5 in the case, but was set free, like Hickey. He faces the same charges and must remain in Brazil.
The eight other suspects are businessmen with Pro10 and THG Sports who are not in Brazil, including Marcus Evans, who owns THG Sports' parent company, as well as football club Ipswich.
Investigators have also found evidence linking 35 other National Olympic Committees to the Marcus Evans group. Rio police will communicate this to other governments but are not expanding their own investigation.