Swimming Australia insists it followed the rules in dealing with a failed drug test by relay world-record holder Shayna Jack, rejecting claims it wasn't transparent about the "embarrassing" result.
The 20-year-old, part of Australia's 4x100 meters freestyle team that set a world record at last year's Commonwealth Games, failed an out-of-competition test late last month and has been suspended.
She returned home days before the start of the world championships in Gwangju, South Korea citing "personal reasons" but news of the incident only emerged in a media report on Saturday, with Jack then denying wrongdoing in an Instagram post.
Swimming Australia admitted the Australian Sports Anti-doping Authority had told it Jack tested positive on June 26.
But the Australian governing body maintained it was required to keep the details confidential "until either Asada or the individual athlete release details of an adverse test result".
Richard Ings, the former head of Asada, questioned this in a tweet and called Jack's explanation for missing the world championships "an untruth".
Swimming Australia chief executive Leigh Russell, who called the test result "bitterly disappointing and embarrassing," insisted the rules were "very, very clear" and they prevented her from speaking out earlier.
Russell said that Jack "wanted to wait until her teammates had finished competing" before announcing the positive test.
The first positive test related to the world championships is disastrous for Australia after Olympic champion Mack Horton's protest against Chinese rival Sun Yang in Gwangju over claims he smashed vials of blood following a test last year.
Russell insisted Horton would have taken the same stance even if he had known of Jack's test result.
"I think that Mack has made a stand for something that he truly believes in," she said.
The championships ended last night, with Caeleb Dressel helping the United States to silver in the 4x100m medley relay to take his medal tally in the meet to a record eight. Dressel won six gold medals, including three on Saturday.
In the women's medley relay, the US set a world record of three minutes and 50.40 seconds.
Katinka Hosszu of Hungary ruled the 400m individual medley, becoming the first woman to win five titles in one event.
Hungarian Tamas Kenderesi, meanwhile, was banned from leaving South Korea after being arrested for alleged sexual harassment.