US star Ryan Lochte was one of four swimmers involved in an incident ©Getty Images

Ryan Lochte is one of four members of United States' swimming team to have been robbed at gunpoint by muggers posing as policemen early this morning, it has been confirmed.

Six-time Olympic champion Lochte was returning to the Athletes' Village in a taxi from a post competition night-out at the French Hospitality House close to Ipanema alongside team-mates Gunnar Bentz, Jack Conger and Jimmy Feigen.

Their taxi was stopped by individuals dressed as policeman.

One pointed a gun at the swimmers before taking their money and belongings.

"Their taxi was stopped by individuals posing as armed police officers who demanded the athletes' money and other personal belongings," said United States Olympic Committee (USOC) chief external affairs officer Patrick Sandusky.

"All four athletes are safe and cooperating with authorities."

It is thought only money and credit cards were stolen, with no Olympic medals taken.

All four had won gold medals as part of US relay teams.

Lochte, Bentz and Conger were all part of the 4x200 metres freestyle squad while Feigen participated in the 4x100m freestyle event.

Security continues to be a huge concern in venues and around the city ©Getty Images
Security continues to be a huge concern in venues and around the city ©Getty Images

It marks the latest worrying security incident after multiple mugging cases, many of which have involved guns.

Two bullets have also been fired into the equestrian venue at Deodoro, while a media bus came under attack - officially from stones although witnesses insist it was gunfire - when travelling back to the main Olympic hub here in Barra da Tijuca.

News of the latest incident filtered out in a particularly confusing way because it was denied and called "absolutely not true" by International Olympic Committee (IOC) Presidential spokesperson Mark Adams before he apologised and said he had been relying on communication from USOC.

"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," Lochte has since told NBC. 

"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, 

"He took our money, he took my wallet - he left my cellphone, he left my credentials."