(AP) The mystery behind the claim that U.S. swimmer Ryan Lochte and three teammates were robbed after a night of partying in Rio de Janeiro deepened Thursday, after officials first blamed him for making it up - then backtracked on some details and acknowledged the Olympians had been confronted by security guards with guns.

The robbery that was or wasn't has become the biggest spectacle outside of the Olympic venues in Rio, and given American swimming a black eye in Brazil after an otherwise remarkable run at the Summer Games.

"No robbery was committed against these athletes. They were not victims of the crimes they claimed," Civil Police Fernando Veloso said during an afternoon news conference Thursday.

Lochte, along with fellow swimmers Jack Conger, Gunnar Bentz and Jimmy Feigen, stopped at the gas station in Barra da Tijuca, a suburb of Rio where many Olympic venues are located. They had been at the French hospitality house celebrating the final night of swimming events at the Rio Games.

A Brazilian police official told The Associated Press that two of the swimmers said Lochte had made the story up. Speaking on condition of anonymity because the investigation was ongoing, the official said the swimmers had tried to open a door at a gas station but it was jammed. They broke the door, and a security guard came to investigate. Then, the official said, the station manager demanded money to pay for the door. The swimmers handed over money and left.

Hours later, the official changed the story and said two security guards pointed guns at the swimmers. The change in the version of events came after police interviewed one of the security guards on Thursday.

The official said the swimmers broke the bathroom door and a soap dispenser inside.

Workers at the gas station went to see what the commotion was about, the official said. At that point, a security guard also came and confronted the swimmers, and pointed a gun. A second guard came behind him and pointed another gun.

Lochte's attorney, Jeff Ostrow, has maintained that there is no question the robbery occurred.