An International Olympic Committee disciplinary commission will investigate the robbery scandal involving U.S. swimmers Ryan Lochte, Jack Conger, Gunnar Bentz and James Feigen.
The Associated Press reported that IOC spokesman Mark Adams acknowledged the panel had been set up, but offered no other details.
Agence France Presse quoted an unnamed IOC official as saying the commission "will see if there is material for a sanction."
The athletes initially told police they were robbed at gunpoint early Sunday morning on their way back from a party outside Olympic Village in Rio de Janeiro.
But two of the swimmers, Conger and Bentz, admitted to fabricating the story after they were detained at the airport late Wednesday while attempting to head back to the United States. The two boarded a flight back to the U.S. late Thursday after being questioned by authorities. Lochte returned to the United States on Monday before any of the news emerged.
Lochte has apologized for his behavior in a robbery scandal in Rio following his competition in the Olympics, releasing a statement Friday on Twitter.
"I want to apologize for my behavior last weekend - for not being more careful and candid in how I described the events of that early morning and for my role in taking the focus away from the many athletes fulfilling their dreams of participating in the Olympics," Lochte wrote.
He continued by justifying his late response, saying he had wanted to wait until his teammates were safely back home in the U.S. before saying anything public.
The 12-time Olympic medal-winning swimmer did not, however, clarify his account of what happened during the night in question, maintaining only that a gun was pointed at his head and noting the stress of navigating a foreign country with an unfamiliar language, particularly at night.
He also noted that a stranger had demanded money before he was allowed to leave — something that Lochte had construed as a robbery, though Rio de Janeiro police sources have said the owner of the gas station where the incident took place was demanding payment for damages after Lochte and his teammates allegedly broke a rest room door.
Brazil could charge swimmers
Brazilian police had said they were considering charging the swimmers with vandalism and giving false testimony after the swimmers admitted they fabricated a story about being robbed at gunpoint.
Feigen has agreed to pay a charity in Brazil nearly $11,000 to settle his part of the scandal, allowing him to return to the U.S., his attorney announced early Friday after lengthy meetings with government and legal authorities in Rio.
US Olympic Committee apologizes
The U.S. Olympic Committee also apologized to Brazil for the false robbery claim.
Fernando Veloso, head of the civil police of Rio, told reporters Thursday that security cameras revealed the swimmers actually visited a gas station early Sunday morning, and that witnesses said they damaged a bathroom, were confronted by an armed guard and left before police arrived.
Brazil's Globo TV on Thursday aired security video of the swimmers showing them arriving at the gas station in a taxi, entering the building, leaving, and later sitting on the curb with their hands up, as instructed by one of the staff members at the gas station.
Veloso said the men left $20 and 100 Brazilian reals to pay for the damage to the bathroom, which included broken mirrors and damage to the door. The police chief also said Lochte was "physically outraged" during the incident and was "probably drunk." But he said Lochte could not be held solely responsible for the incident. "That would be a premature assumption of guilt," Veloso said.
Rio Games: 'Give these kids a break'
Despite the visible ire of the police, Rio Games organizers defended the swimmers, insisting, "Let's give these kids a break."
Rio 2016 spokesman Mario Andrada told reporters, "They competed under gigantic pressure. ... They had fun, they made a mistake, life goes on."
The gas station is close to Olympic Park, where the sporting events have been overshadowed over the past two weeks by a series of muggings and robberies, including incidents involving other athletes and two visiting government ministers.
Meanwhile, nine Australian athletes were detained overnight and fined for tampering with their identity cards so they were able to attend their home country's basketball semi-final. The athletes were charged with falsifying a document, and each fined about $3,120. Brazilian authorities say their passports are being held until the fine is paid.