The Brazilian authorities have charged US swimming star Ryan Lochte with making a false statement about being robbed at gunpoint during the Olympics, police said.

The 32-year-old gold medal-winner risks a jail sentence, Brazilian media quoted a police official as saying, although the judicial authorities had yet to confirm that.

"Ryan Lochte was charged with the crime of falsely reporting a crime," police said in a statement, adding that the case had been referred to the courts.

The police statement said they had recommended the courts issue a summons for Lochte to be questioned.

"Once he is summoned, whether he turns up or not, the penalty is the same: one to six months' prison," the news website G1 Rio quoted police official Clemente Braune as saying.

"If he is summoned and does not turn up to the hearing, the trial will go ahead in the accused's absence until the final sentence is given."

Vandalized bathroom

Lochte apologized last week for saying that he and three teammates had been mugged on their way back from an all-night party by robbers pretending to be police.

Rio police chief Fernando Veloso later told a news conference that the swimmers were not robbed but detained when they tried to flee after vandalizing a gas station bathroom.

The tale humiliated first the Brazilian hosts of the Games and later Lochte's own Team USA after police contested his story.

Top sponsors such as Speedo and Ralph Lauren abandoned Lochte this week.

"I'm taking full responsibility for it," Lochte said in an interview broadcast late Saturday.

"I over-exaggerated that story and if I had never done that, we wouldn't be in this mess."

Drunken urination

Lochte had earlier issued a written apology that was widely ridiculed online as half-hearted.

In the later NBC interview, he also admitted he was still intoxicated when he gave his initial account of the incident, adding: "I let my team down."

Following the incident, Lochte flew back to the United States, while the other three swimmers -- Gunnar Bentz, Jack Conger and Jimmy Feigen -- stayed in Brazil.

Police last week released closed-circuit TV footage and other evidence about the events at the gas station.

The athletes, who appeared intoxicated, stopped in a taxi at the gas station to use the bathroom during the early hours of the morning.

Lochte and the others then vandalized the area near the bathroom and, according to the manager, urinated on the walls.

Confronted by a security guard, they tried to leave. When the confrontation escalated, the security guard took out his pistol and made them sit on the ground.

After paying around $50 in compensation for the damage, they left unharmed and returned to the athletes' village.

"There was no robbery of the kind reported by the athletes," Veloso said.

Lochte's claims embarrassed the Olympic authorities, highlighting security worries at the Olympics.

Brazil had deployed 85,000 police and soldiers to secure the Games.

Lochte could also face disciplinary action over the incident by USA Swimming and the International Olympic Committee.

One US company threw Lochte a lifeline on Thursday, however. Pine Bros. Softish Throat Drops said it would launch a series of ads featuring Lochte with the slogan: "Forgiving on Your Throat."