UPDATE 1:17 p.m. ET Sunday: RIO DE JANEIRO (AP) — The U.S. Olympic Committee says Ryan Lochte and three other American swimmers were robbed by armed men who stopped their taxi.

USOC spokesman Patrick Sandusky says Lochte and the others left the French Olympic team's hospitality house early Sunday in a taxi headed for the athletes village, hours after the last night of Olympic swimming.

He says "the taxi was stopped by individuals posing as armed police officers who demanded the athletes' money and other personal belongings."

Sandusky says the four swimmers are "safe and cooperating with authorities."

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The official Twitter account of Fox News Sports announced Sunday that U.S. Olympic swimmer Ryan Lochte was held at gunpoint at a party in Brazil. In a series of tweets, the network cited the athlete's mother, and even Lochte himself.

Reports stated that Lochte was invited to the alleged party by Brazilian swimmer Thiago Pereira and that three teammates were with him. USA Today reported that Lochte and at least one other teammate were robbed at the party.

BREAKING: @USASwimming Gold medallist Ryan Lochte has been held up at gunpoint at a party in Brazil.
Details on @FOXSportsNews 500.

— Ben Way (@BenWayFOX) August 14, 2016

Lochte invited by Brazilian swimmer Thiago Pereira, and is now safe at @USASwimming base. @FOXSportsNews told 3 teammates were with him.

— Ben Way (@BenWayFOX)

August 14, 2016

Lochte called his mother Ileana immediately afterwards. She told @FOXSportsNews it was "terrifying" and has just left her hotel to meet him.

— Ben Way (@BenWayFOX) August 14, 2016

LOCHTE UPDATE: @TeamUSA 's Jenn Suhr exclusively told @FOXSportsNews: "it definitely would have been terrifying. I'm just glad they're safe"

— Ben Way (@BenWayFOX) August 14, 2016

LOCHTE: @TeamUSA 's Jenn Suhr: "when you're in another country you don't know of, it's not the smartest idea to go places you're unsure of.

— Ben Way (@BenWayFOX) August 14, 2016

The Associated Press reported that Rio Olympic organizers were aware of an unspecified "issue." Later Sunday morning, however, IOC spokesman Mark Adam called the report "absolutely not true," according to Lochte and USOC.

A spokesman for the USOC said it was trying to get more information. Lochte's mother, Ileana Lochte, did not immediately return a call from the AP.

Lochte, 32, swam in two events at the Rio Games, winning gold in the 4x200-meter freestyle relay.