Ryan Lochte

RIO DE JANEIRO — Ryan Lochte, the 12-time Olympic medal winner who claimed to have been robbed here last weekend by men identifying themselves as police officers, issued an apology on Friday “for my behavior” in an episode that has cast a pall over the Games.

The apology came as testimony emerged from other American swimmers challenging Mr. Lochte’s initial version of events. In sworn statements to investigators, the other swimmers described Mr. Lochte, 32, as drunk and unruly, saying he had damaged property at a gas station and later misrepresented what happened.

The case has ignited a debate that goes well beyond sports, eliciting an apology from American Olympic officials and outrage from Brazilians who accuse Mr. Lochte of smearing Rio’s reputation as it held one of the most important international events in Brazil’s history.

In his original account, Mr. Lochte said he and three other American swimmers had been pulled over by armed men calling themselves police officers, one of whom put a gun against his head before taking the cash from his wallet.

But police investigators said Thursday that Mr. Lochte had fabricated central elements of the encounter. The investigators said the swimmers had vandalized a gas station bathroom after leaving a lavish party and were confronted over the damages by security guards. At least one of the guards brandished his gun in their direction, the police said.

“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,” Mr. Lochte said in a statement on Instagram.

Mr. Lochte did not give a full account of what happened during the episode, or explained the ways in which his earlier depictions of events were inaccurate. But he insisted that a gun was pointed at him and that he was forced to hand over money.

“It’s traumatic to be out late with your friends in a foreign country — with a language barrier — and have a stranger point a gun at you and demand money to let you leave,” he said in the statement.

In sworn statements to Brazilian investigators, Mr. Lochte’s teammates said that he was drunk and disorderly, had damaged property and was in need of calming down as they discussed the situation with an armed security guard.

U.S. swimmer Ryan Lochte’s four commercial sponsors dropped the 12-time Olympic medal winner Monday in response to the incident eight days ago in which he falsely claimed he and three teammates had been held up by armed robbers at a Rio de Janeiro gas station.

The decisions by Speedo, Ralph Lauren, Airweave and Gentle Hair Removal came after Lochte admitted to “over-exaggerating” the armed-robbery claim, an assertion that overshadowed much of the second week of the Summer Olympics that concluded Sunday.

Lochte, meanwhile, said he would continue to swim even if sanctioned by the U.S. Olympic Committee for his lack of honesty.