RIO DE JANEIRO, Brazil (AFP) — Allegations that star US swimmer Ryan Lochte invented a story about him and three team-mates being mugged at gunpoint in Rio strengthened yesterday with video footage showing them in a gas station altercation.

The controversy took a dramatic new twist after the leaking of security camera footage from a gas station on Brazil’s Globo television. This came hours after two of the swimmers were hauled off a plane about to leave Rio de Janeiro for the United States and taken in for questioning.

The video footage appears to support police accusations that the medal-winning swimmers vandalised a gas station bathroom where they had stopped off after all-night partying. They were then detained by a security guard.

The four swimmers are seen in the video getting out of a taxi after a man identified as the security guard approaches. Later they are seen being made to sit on the ground.

Brazil’s G1 site quoted police saying the athletes broke the gas station’s bathroom door and started a confrontation with the armed security guard, who pulled out his weapon and made them wait for police to arrive.

This version of events is a far cry from 32-year-old Lochte’s claims.

The swimmer, one of the most visible faces of the Olympics and winner of six gold medals, told media that the four had been robbed at gunpoint by a man claiming to be a policeman.

His report caused the Olympic authorities huge embarrassment, highlighting security worries at an Olympics where Brazil has deployed 85,000 police and soldiers — double the number used in the 2012 London Games.

However, the authorities soon raised doubts over the veracity of the allegation, and the swimmers could face charges of filing a false claim with police.

A judge on Wednesday ordered the swimmers to be detained and their passports confiscated.

Lochte had already flown back to the United States. However, two other athletes — Jack Conger and Gunnar Bentz — were removed by police from a plane just about to take off late Wednesday.

The fourth, James Feigen, was also still in Brazil.

“The three US Olympic swimmers… are cooperating with authorities and in the process of scheduling a time and place today to provide further statements to the Brazilian authorities,” said Patrick Sandusky, spokesman for the US Olympic Committee.