Nick D’Arcy and Kenrick Monk uploaded a photo of themselves posing with a pistol and shotgun to Facebook and Twitter while in the US for a swim meet.
However, Swimming Australia ordered the swimmers to remove the pictures from the social networking sites.
“Swimming Australia became aware of inappropriate photos posted on athletes’ Facebook pages and Twitter accounts this morning, and instantly contacted the athletes involved to ask for them to be removed under Swimming Australia’s Social Media Guidelines,” the organisation said in a statement.
“The photos have been removed. Swimming Australia does not condone the posting of inappropriate content on Facebook, Twitter or any social media platform, and this is a timely reminder for athletes to be more responsible to themselves, the public with whom they engage through social media, and the reputation of the sport.”
Both athletes have been involved in controversy before.
D’Arcy missed the 2008 Beijing Olympics and the 2009 Rome world championships after being charged and eventually convicted of assaulting former swimmer Simon Cowley in a Sydney bar in 2008.
Monk broke two bones in his elbow in October and claimed he was the victim of a hit-and-run – before admitting he actually injured himself in a skateboarding accident.