U.S. swimmers Gunnar Bentz and Jack Conger arrived at a police station on Thursday (August 18) where they were expected to be questioned over an alleged robbery at the weekend.
Brazilian police stopped the Olympians from boarding a flight home on Wednesday (August 17) night to question them about how they and two team mates were robbed at gunpoint in Rio de Janeiro at the weekend, after a judge raised doubts over their accounts.
A third swimmer, James Feigen, is in contact with Brazilian authorities and plans to make further statements to them on Thursday, said a spokesman for the U.S. Olympic Committee (USOC).
Federal police also want to question U.S. gold medallist swimmer Ryan Lochte, one of swimming's most decorated Olympians, but he had already flown home to the United States on Monday, a police spokesman said.
The four swimmers have said they were robbed by gunmen while returning to the Athletes' Village in a taxi in the early hours of Sunday (August 14) after a party - an incident that stoked fears for the safety of athletes and visitors at South America's first Games.
The Rio Olympics have been dogged by a series of security scares, including the robbery of two visiting government ministers, a mugger being shot dead outside the opening ceremony and stray bullets being fired into the equestrian centre.
However, in the case of the four swimmers, police sources have said investigators have not found any evidence so far to back up their accounts.
Television images showed U.S. Olympic swimmers Gunnar Bentz and Jack Conger trying to leave Rio's international airport in the early hours of Thursday surrounded by media after they were not allowed to board their flight back to the United States.
A spokesman for the U.S. Olympic Committee (USOC) confirmed the two men were taken from their flight.
Earlier on Wednesday, a judge had ordered police to seize the passports of Lochte and Feigen to prevent them leaving the country, apparently unaware that Lochte had already left.
Police have taken the passports of Bentz and Conger pending their testimony, O Globo newspaper said on its web site.
People magazine reported that Lochte was spotted at an airport in North Carolina on Wednesday with his girlfriend, Kayla Rae Reid, a Playboy model. Reuters could not verify this.
Lochte's attorney did not return calls for comment.
