Rio 2016 organizers said on Friday that the Brazilian people were disappointed by the four American swimmers who fabricated a mugging story during the Rio Olympic Games.

Ryan Lochte and fellow US swimmers Gunnar Bentz, Jack Conger and Jimmy Feigen last week claimed they were robbed at gunpoint, which drew huge media attention and led to increasing concerns over the Games security which had long been criticized.

Later surveillance footage and an investigation by Brazilian authorities showed that they had vandalised a gas station bathroom and had handed over money to armed security guards who had prevented them from leaving.

"Understand that the Brazilian population was quite disappointed in the actions and the facts," said Rio 2016 spokesperson Mario Andrada.

"We got 1,800,000 people on Rio 2016 Twitter complaining about the whole thing. The mentions around this case were 2.5% of the total mentions we had since the beginning of the Games, so it's clear the Brazilian population felt humiliated by the early part of the issue," he said.

Early on Friday, Lochte posted a letter of apology on his Twitter account.

"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," he said on Twitter.

"I should have been much more responsible in how I handled myself, and for that am sorry to my team mates," he said.

The 32-year-old Lochte, Bentz and Conger have returned to the United States, while Feigen was still in Brazil on Friday morning. Feigen had agreed to pay 11,000 US dollars to a Brazilian charity, police said. His passport would be released upon providing a receipt.

Andrada said the country will accept the swimmer's apology and hoped this matter comes to an end.

"I think that the Brazilian population will accept his apologies and we want to put this matter to an end and I don't see this as a fact that will mark these Games," he said. "As a matter of fact, I don't think this carries much weight on any negative effect on the Olympic Games.

"What goes into history is the huge contribution by the athletes and also by the artists when you think about the closing ceremony," he said.

The Rio Olympic Games, starting on Aug. 5, comes to a close on Sunday.