Olympic Gold medalist Ryan Lochte and three of his teammates were held up at gunpoint in Rio, according to the U.S. Olympic Committee.

Officials provided few details about the incident. Police are investigating.

Crime was already a top concern before the Rio Games began, as Brazil’s economic crisis deepened, pushing up unemployment and poverty rates. The Rio state government deployed a huge security force, and the streets surrounding the Olympic Park and the athletes’ village sometimes look like a military compound.

But, nonetheless, crimes have occurred more frequently than at other recent Olympics. On the night of the opening ceremony, the chief of security was mugged at knife point. Two coaches for Australia’s rowing team were attacked and robbed in the Ipanema neighborhood, while some Olympians were robbed of belongings in the athletes’ village during a fire drill. Bullets have landed in the equestrian venue, and a bus carrying members of the news media was attacked, its windows shattered.

“Their taxi was stopped by individuals posing as armed police officers who demanded the athletes’ money and other personal belongings,” a spokesman for the U.S.O.C. said. “All four athletes are safe and cooperating with authorities.”

Lochte told NBC News:

“We got pulled over, in the taxi, and these guys came out with a badge, a police badge — no lights, no nothing, just a police badge — and they pulled us over. They pulled out their guns, they told the other swimmers to get down on the ground — they got down on the ground. I refused — I was like, we didn’t do anything wrong, so — I’m not getting down on the ground.

“And then the guy pulled out his gun, he cocked it, put it to my forehead, and he said, ‘Get down,’ and I put my hands up. I was like, whatever. He took our money, he took my wallet — he left my cellphone, he left my credentials.”

The confusion surrounding the incident centered on the International Olympic Committee, which denied the robbery took place. The IOC said the robbery was “absolutely not true." Eventually, the IOC claimed it was just repeating the information passed along by American Olympic officials.

“They said they spoke to Lochte, and he said it wasn’t true,” the IOC spokesman said. “I guess that may change.”

Brazil's minister of Sport, Leonardo Picciani seemed to suggest the athletes were at fault, according to the New York Times.

“Security in the Games has been absolutely efficient,” Picciani was quoted as saying by the newspaper Estadao. “The delegations have not had problems. Those who have bought tickets have not had problems.

“Certainly no athletes have had problems in their places of accommodation, their training facilities and the athletes' village.”