Australian Athletes

Some athletes also showed "unacceptable behaviour" on their flight home, officials added.

But Australia team boss Ian Chesterman said no disciplinary action would be taken as the athletes had apologised.

He added that the damage was "minor" and that it was "not the hardest thing to break the cardboard bed".

Chesterman did not name the athletes or the sport they represented.

But the Australian Olympic Committee said the national governing bodies of football and rugby union were investigating reports of rowdy behaviour on a flight into Sydney last Friday.

Earlier today, Sports Illustrated confirmed US pole vaulter Sam Kendricks had tested positive and is out of the Tokyo Olympic games.

As a matter of precaution, Australians and others identified as close contacts will now be tested and will await their results.

Results can be returned in about six hours, but that will be a long six hours for those waiting to have their concerns confirmed or put aside, not to mention the stress of having training cut short.

This is precisely the scenario many had predicted ahead of the games and now the system will be tested in full.

Australia's athletes have been banned from two of Rio de Janeiro's popular beaches after dark due to security concerns.

American six-time Olympic gold medallist Ryan Lochte was confirmed to have been held up at gunpoint on Sunday, while two Australian rowing coaches were robbed at knifepoint shortly after the Games' opening ceremony.