Update - 11.25am: Inspector Ricardo Barbosa told a press conference in Rio that they were offering tickets for more than four times the original price.
Inspector Barbosa said: "Several elements of our inquiry confirm that the company involved is acting on an international scale.
"That company, which goes by the name of THG, was seeking to make a profit through the irregular sale of tickets for the Rio de Janeiro games.
"A ticket for the Games opening ceremony, originally costing $947, was resold for $8,000."
Earlier: The Olympic Council of Ireland is investigating why tickets allocated to the organisation were found on two men arrested by Rio de Janeiro police.
Irish national Kevin Mallon, one of the heads of British ticketing and hospitality provider THG Sports, was arrested with tickets for the Rio Games, police said. He is accused of conspiracy and helping sell tickets illegally.
The state's investigative police also arrested a company employee who was working as an interpreter during the games in a raid on Friday.
Agents seized more than 1,000 tickets being sold for "very high" fees.
The OCI name was visible on tickets displayed by police, but the Olympic Council of Ireland said they had "no knowledge" of the two men arrested.
"The OCI has launched an immediate investigation with our (authorised ticket reseller) ATR, Pro10, into how the individuals were allegedly in possession of OCI allocated tickets," the Olympic Council of Ireland said in a statement.
"The OCI strictly adheres to the IOC regulations around ticket allocation, sale and resale. We are treating this matter with the utmost seriousness."
Police said THG Sports was part of an alleged ticket-touting scheme that was uncovered during the 2014 World Cup.
THG Sports, which is not the Olympic Council of Ireland's official ticketing partner, does not mention Mr Mallon on its website.