RIO DE JANEIRO • Reports emerged yesterday that Ryan Lochte and three other US Olympic swimmers claiming to have been mugged at gunpoint in Rio in fact got into a fight with an armed gas station security guard.

The unconfirmed reports on ABC News and Brazilian news sites said an altercation occurred when the swimming stars had been out partying and that the incident was caught on security camera footage.

Brazil's G1 site quoted Rio police saying that the athletes had stopped at the gas station in a taxi to use the bathroom.

Globo website quoted the station manager saying the Americans urinated on the station wall. They broke the bathroom door and tried to leave without paying for the damage, but a security guard pulled out his weapon and made them stay until police arrived, prompting a confrontation, G1 reported.

ABC quoted an unidentified Brazilian police source saying CCTV footage shows a swimmer "breaking down the door to the bathroom at the gas station and fighting with a security guard".

Lochte originally said that he, Jack Conger, Gunnar Bentz and James Feigen were robbed by someone claiming to be a policeman early on Sunday.

The report caused the Olympic authorities huge embarrassment, highlighting security worries at an Olympics where Brazil has deployed 85,000 police and soldiers - double the number used at the 2012 London Games.

However, police soon raised doubts over the veracity of the allegation and the swimmers could face charges of filing a false claim.

Bentz and Conger were pulled off their flight for questioning after a judge found inconsistencies in the swimmers' accounts.

Lochte, who had returned to the US before he could be questioned further, denied the swimmers had fabricated their story in an interview with NBC on Wednesday. "I wouldn't make up a story like this nor would the others - as a matter of fact, we all feel it makes us look bad," he was quoted as saying.

Rio Games organisers yesterday defended the four swimmers, saying they were just kids who were having fun and made a mistake.

"These kids tried to have fun, they tried to represent their country to the best of their abilities," Rio 2016 spokesman Mario Andrada told reporters said, without elaborating.

"They competed under gigantic pressure. Let's give these kids a break. Sometime you take actions that you later regret. They had fun, they made a mistake, life goes on."

AGENCE FRANCE-PRESSE