US Olympic swimmer Ryan Lochte 'robbed in taxi at gunpoint' in Rio

US swimmer Ryan Lochte was reportedly robbed at gunpoint when his taxi was held up as he left a party in Rio de Janeiro.

According to a spokesman for Brazilian swimmer Thiago Pereira, gold medallist Lochte told Pereira that the taxi he was in was robbed.

"Thiago and his wife went yesterday night to a birthday party for a common friend with Lochte in the France House," the spokesman said.

"He parted ways with Lochte when he returned to his hotel with his wife.

"Today in the morning he received the news about Lochte's incident, so he called him and Lochte told him he was fine, and said the taxi he was in got robbed."

Meanwhile, NBC News reported that Lochte himself had confirmed to the channel's Billy Bush that he and "three other swimmers" had been robbed at gunpoint.

Fox News had originally reported Lochte was held at gunpoint during the hold-up, quoting the swimmer's mother as saying the incident has been "terrifying" and saying they had been forced to hand over their wallets.

However, the International Olympic Committee (IOC) initially rejected that there had been a gun involved, which said the United States Olympic Committee (USOC) had spoken to the athlete directly and it was not true.

Rio 2016 committee spokesman Mario Andrada said there was no confirmation that Lochte had been held at gunpoint, but said they had received a report there had been an "issue" with him.

"We are just waiting for more information and all information that we can share with you in terms of being more solid, we heard about the event but we don't have more information so far," he said.

USOC said it was investigating to find out the "truth and details".

Lochte is on the US men's swimming team and, along with teammates Michael Phelps, Conor Dwyer, and Townley Haas, won the gold medal in the 4200m freestyle relay.