U.S. swimmers Jack Conger, left, and Gunnar Bentz are escorted through the international terminal at Miami International Airport upon their arrival to the United States from Rio de Janeiro Friday morning. (Angel Valentin/Getty Images)

Five days after telling the world he and three U.S. Olympic swimming teammates were robbed at gunpoint on a Rio de Janeiro highway, an account later called a lie by Brazilian authorities, 12-time Olympic medalist Ryan Lochte apologized Friday for “not being more careful and candid” about the incident.

“I want to apologize for my behavior last weekend,” began Lochte’s statement, posted to his social media accounts. It ended: “I should have been much more responsible in how I handled myself.”

Lochte, 32, has been in the United States since Tuesday, leaving Brazil before authorities ordered his passport seized for what they called a false police report, while teammates Gunnar Bentz and Jack Conger regained their passports and flew out of Rio de Janeiro on Thursday night after cooperating with investigators. At least one of them refuted Lochte’s account of the incident, police said.

A poster parodying Ryan Lochte hangs at the Olympic Stadium in Rio de Janeiro, site of the track competition. (Dominic Ebenbichler/Reuters)

The fourth American swimmer, Jimmy Feigen, paid a fine equivalent to $10,800 to a Brazilian nonprofit sporting institution Friday and in exchange recovered his passport and was allowed to leave the country. Feigen had faced the equivalent of a misdemeanor charge of “False Communication of a Robbery” and reached a plea bargain to pay the fine. Officer Marcelo Carregosa, who is second in charge of the special tourist police station in Rio, said the same offer has been made to Lochte, who will be required to either appear in Brazil or provide testimony in the United States.

On Thursday, Brazilian police claimed Lochte had made up his tale of the four swimmers being held up early Sunday morning by armed assailants who identified themselves as police, releasing surveillance video that appeared to show the athletes tearing a door off a gas station restroom not far from the Athletes’ Village. When the swimmers tried to leave without paying for the damage, according to the authorities, security guards produced a gun and ordered them to stay until police arrived. The swimmers eventually handed over the equivalent of $51 and left.

On Friday, an eyewitness who had helped translate between the swimmers and the gas station employees told a Brazilian television station that the swimmers offered to pay for the damages at first.

“They started to ask in English, ‘How much is it to pay for this?’ ” Fernando Duluz, identified as a local DJ, told the television reporter. “At no point did anyone touch them — the security, no one. There was no, ‘You are under arrest,’ Nothing. [The employees] wanted me to ask them if I should call the police, and [the swimmers] did not want to call the police. The guys said, ‘Please, please, no police.’ ”

Late Friday, Bentz released a detailed statement through the University of Georgia, in which he said he did not witness anyone damage the restroom door but that “Ryan pulled to the ground a framed metal advertisement that was loosely anchored to the brick wall.” He said two security guards pointed guns at the swimmers and “one of the guards said that we needed to pay them in order to leave.” Bentz added that, “I am confident that some video angles have not been shown that would further substantiate my account.”

If Lochte’s apology fell short of a full mea culpa for his actions, that apparently was by design; his attorney, Jeff Ostrow, has maintained Lochte stands by his characterization of the incident as a robbery at gunpoint. “That part of the story will never change,” Ostrow told USA Today on Friday. “We stand behind that.”

Brazilian authorities say Ryan Lochte and several other U.S. swimmers fabricated their story about being robbed at a gas station on Aug. 14. Here's why. (Monica Akhtar/The Washington Post)

In Brazil, the Lochte affair was widely viewed as a blatant attempt to use Rio de Janeiro’s reputation for crime and violence — one that the swimmer’s initial account only bolstered — to whitewash a night of drunken hooliganism.

“In respect to the swimmers, I confess my only feeling is of embarrassment [and] contempt,” Rio de Janeiro Mayor Eduardo Paes said. He called it a shame that “there are some character failings” on the part of the swimmers.

The International Olympic Committee on Friday set up a disciplinary commission to investigate the incident, according to the Associated Press. Such bodies have the power to issue sanctions. The U.S. Olympic Committee, USA Swimming and FINA, the sport’s world governing body, also may impose punishments.

While the USOC apologized late Thursday night for the “distracting ordeal,” and USA Swimming said in its own statement that it does not condone “the lapse in judgment and conduct” on the part of its athletes, there was no immediate word as to what punishments the swimmers will face. A USA Swimming spokesman said there was no set timetable for a decision on disciplinary action against the swimmers, and the USOC said no decision would come before the Games end.

In its statement Thursday night, USA Swimming Executive Director Chuck Wielgus said the organization will review the incident and “determine any further actions.”

Lochte has said he planned to take an extended break following the Rio Games but that he planned to compete at the 2020 Tokyo Games.

“I am not done with the sport,” he said before the Games began. “There is so much more I want to accomplish within the sport of swimming.”

Rick Maese contributed to this report.