The Brazilian authorities have
stopped US swimmers Gunnar Bentz and Jack Conger from boarding a flight
at Rio de Janeiro airport, the US Olympic Committee has confirmed.
The two men were taken off a plane, bound for the US, for questioning late on Wednesday and released hours later.Two teammates - Ryan Lochte and James Feigen - were barred from leaving the country, but Lochte had already left.
Police have queried their accounts of a robbery they reported in Rio on Sunday.
The four swimmers said they had been robbed at gunpoint in a taxi in Rio.
But police say their account of when they arrived at the Olympic village does not square with CCTV recordings.