A Brazilian judge has ordered American swimmers Ryan Lochte and James Feigen  to remain in the country and has ordered the seizure of the pair's passport.

The news comes as authorities investigate reports that the pair where robbed at gunpoint, but officials claim that they have found little evidence to substantiate those allegations.

A police official told The Associated Press that police can't find their taxi driver or witnesses. They also say that the account doesn't square with CCTV footage.

Local media report that Lochte had left the country before the order was issued. 

Lochte told police that he and team mates James Feigen, Gunnar Bentz and Jack Conger had all been at a party in the French Olympic team's house on Saturday evening.

Whilst returning to their own accommodation, their taxi was stopped by armed men posing as police and they were robbed.