Brazilian authorities removed two U.S. swimmers, Jack Conger and Gunnar Bentz, from their flight home on Aug. 17 and prevented them from leaving the country. Here's why. (Monica Akhtar/The Washington Post)

Brazilian police Thursday accused swimming star Ryan Lochte of fabricating his story of being held up along with three of his U.S. Olympic teammates by armed assailants. But the authorities also acknowledged a gun was pulled on the foursome by a security guard early Sunday at a Rio de Janeiro gas station, where the swimmers apparently damaged property at the end of a late-night excursion.

The police statement contradicting Lochte’s account was later corroborated by a lawyer who represented two of Lochte’s fellow U.S. swimmers. The episode threatened to overshadow the Rio Games and what has been a stellar performance by U.S. athletes, led by the American swimming team that ended its competition here last week.

“No robbery was committed against these athletes,” Fernando Veloso, chief of the Rio de Janeiro police investigative division, said during a packed news conference Thursday afternoon. “They were not victims of the crimes they claimed.”

Early Friday, Breno Melaragno, the lawyer for swimmer Jimmy Feigen, said that under an agreement reached with a Brazilian judge, Feigen will donate roughly $10,800 to an unnamed institution and then depart the country, the Associated Press reported.

Late Thursday, the U.S. Olympic Committee issued a statement that acknowledged a version of events that involved an argument spurred by “an act of vandalism” committed by “one of the athletes.” The statement concluded, “We apologize to our hosts in Rio and the people of Brazil for this distracting ordeal in the midst of what should rightly be a celebration of excellence.”

All of these statements came after Team USA swimmers Gunnar Bentz and Jack Conger, who were pulled off their U.S.-bound flight Wednesday by Brazilian authorities, were questioned about the incident at a police station. According to Veloso, one of the two confirmed to investigators that Lochte’s account had not been altogether true.

Lochte, 32, one of the most decorated U.S. Olympic athletes, was in the United States, having left Rio de Janeiro on Tuesday, but Bentz, Conger and Feigen remained in the city, their passports confiscated while the authorities complete their investigation.

No charges have been filed against the swimmers — and the potential charges of falsely reporting a crime and damage to property likely would not preclude the swimmers from leaving the country — but the incident has set off a firestorm locally. Brazilians have reacted with anger and indignation to an apparently false crime report that only served to boost the perception of Rio de Janeiro as a lawless, chaotic city that was unprepared to host an Olympics.

Many Brazilians believe Lochte’s initial story preyed upon that reputation.

“I’m very aware of the chaos of the city, of the violence, of all the Brazilian problems,” said Tati Leite, a 40-year-old film producer in Rio de Janeiro. “Taking advantage of this, to hide misbehavior, I felt offended.”

Veloso, the Civil Police chief, said Lochte and the others owed Cariocas — the local term for Rio de Janeiro natives — an apology for having “stained” the city “for a fantasy.”

As the American swimmers left the police station Thursday evening, they were swarmed by a crowd of journalists amid shouts of “liars” by some, in English.

Just after 8 p.m. Rio time on Thursday, attorney Sergio Riera said Bentz and Conger had been given authorization to leave Brazil by the special Olympic court. “They are on their way to the airport,” Riera said.

At the airport, Marcelo Belmonte, a volunteer from Rio 2016 transport team, said the two American swimmers passed through security at a special entrance near the American Airlines desk in Terminal 2. Jefferson Bonfim, a baggage employee with American Airlines, said they were scheduled to board Flight 990 destined for Miami.

Veloso told the Brazilian newspaper O Globo that Feigen was being interviewed by police Thursday evening.

Rather than an armed robbery at the hands of assailants who pulled over their taxi and identified themselves as police, as Lochte originally claimed, the incident appears to have stemmed from a drunken pit stop at a gas station bathroom in the West Rio neighborhood of Barra de Tijuca, near the Athletes’ Village, at around 6 a.m. Sunday.

Surveillance footage from the gas station appears to show at least one of the swimmers — who completed their Olympic competition Saturday — pull off the metal door to the bathroom.

In the video, released by Brazilian police, gas station employees observe the athletes, then escort them out of the bathroom. In another clip, from a different camera angle, the athletes quickly seat themselves on the ground and raise their hands, as if ordered by a person with a gun.

Veloso confirmed that one of the security guards produced the weapon to “contain” the swimmers so they could not leave without paying for the damage. “The firearm was used in a situation in which they were contained. When they were contained, the firearm was put away,” he said.

Riera, the attorney who represented Bentz and Conger, said the four swimmers arrived at the gas station seeking to use a restroom, but upon finding there wasn’t one available, two of the men urinated at the back of the station and Lochte punched an advertisement in a metal frame, which fell noisily to the ground and attracted the attention of staff.

Riera said that when his clients saw the armed robbery story Lochte had told NBC, “They knew it was a lie. But they did not have to go public. They thought this would be forgotten. They did not think it would have a more serious consequence.”

Lochte’s attorney, Jeff Ostrow, did not immediately return a telephone message at his Fort Lauderdale, Fla., office Thursday. The day before, Ostrow said the incident happened “exactly the way Ryan described it” under oath to Brazilian police Sunday. “They were robbed at gunpoint — the way he described it,” Ostrow said.

But Lochte’s account has changed at least twice. He apparently denied that any incident at all had occurred when first asked about it by a U.S. Olympic Committee official, who was responding to media accounts of a robbery — accounts attributed to Lochte’s mother, Ileana. The denial led to a bizarre series of events Sunday, in which an International Olympic Committee spokesman said the reports of an alleged robbery involving Lochte were “absolutely not true,” attributing the information to the USOC, then later pivoted and apologized to Lochte and the others for issuing the initial denial.

Lochte eventually provided a detailed account of the alleged incident to NBC in an on-camera interview, saying the assailant claimed to have been a police officer, demanded the four swimmers hand over their money and wallets and pressed a gun to Lochte’s forehead when he initially resisted. The story made global headlines, underscoring the widespread perception that the 2016 Games have been beset by problems of crime and violence.

By Wednesday, as doubts about the original account grew and as the other swimmers were blocked from leaving the country, Lochte, from the safety of the United States, altered his account slightly during an off-camera interview with NBC “Today” host Matt Lauer. This time, Lochte said the taxi had pulled into a gas station, instead of being stopped by the assailants, according to Lauer, who spoke on NBC’s Olympics telecast Wednesday evening. Lochte also backed off earlier claims that the assailant put a gun to his forehead.

Lochte, 32, was one of the most celebrated and visible American athletes in Rio this month, a major figure in his sport, a four-time Olympian and a centerpiece of NBC’s marketing push heading into the 2016 Games. A gold medal in the men’s 4x200-meter freestyle relay gave him six career Olympic gold medals and 12 overall, the latter figure ranking behind only U.S. teammate Michael Phelps among male swimmers in history.

Feigen, 26, made his second Olympic appearance in Rio, while the 20-year-old Bentz and 21-year-old Conger — the latter a three-time All-Met swimmer of the year from Rockville — were first-time Olympians. All three won their first Olympic gold medals in last week’s swimming competition, helping the United States dominate the medal tables, with 33 overall, including 16 golds.

Following the end of the swimming competition Saturday night, Bentz, Conger, Feigen and Lochte left the Athletes’ Village for a party at France’s hospitality house on the Rodrigo de Freitas lagoon. They left the party at about 5:47 a.m., according to a police surveillance video, and didn’t arrive at the Athletes’ Village for an hour.  

After leaving the party, the swimmers’ taxi pulled into a Shell gas station on Avenida Armando Lombardi at around 6 a.m. 

Veloso presented a possible motive for the deception, saying two of the swimmers had some involvement with two girls at the party they were leaving and may have wanted to disguise the fact.

“The first information came from a driver who took two young women who left the event. These young women . . . had made out with the swimmers,” Veloso said. The swimmers “had a reason to tell a story that wasn’t true.”

In an Olympics full of moments of athletic brilliance — by Phelps and Katie Ledecky in swimming, by Simone Biles in gymnastics and Usain Bolt in track, among others — the Lochte affair has dominated headlines for the better part of a week, and even the Rio 2016 organizers seem to wish it would simply go away.

Asked whether he expected an apology from Lochte to cancel out the one the Rio organizers issued to him in the wake of Sunday’s news, Mario Andrada, spokesman for Rio 2016, said none was necessary.

“Let’s give these kids a break,” Andrada said. “Sometimes you take actions that you later regret. Lochte is one of the best swimmers of all time. They had fun. They made a mistake. Life goes on.”

Jerry Brewer and Sally Jenkins in Rio de Janeiro and Carol Morello in Washington contributed to this report.