'Ridiculous choice'

Magnussen received A$10,000 ($10,300) from the AOC for winning a silver medal in the men's 100 meters freestyle, while Targett and D'Orsogna were paid A$7,500 for winning bronze as part of the 4x100m medley relay team.

The athletes face the possibility of losing part or all of those rewards as well as funding for preparation for major events, including the 2016 Olympic Games.

Magnussen was hot favorite to win the 100 freestyle in London and suggested the weight of expectation on him contributed to him agreeing to take the drug.

"I think one of the reasons that I agreed to go along with this night was I was feeling under so much pressure and it had been building for the best part of a year," the 21-year-old said.

"In hindsight, a ridiculous choice, and a ridiculous method to do that.

"I have a lot of regrets, but I don't feel think it affected my performance. My preparations continued on as per normal immediately following the next day."

Misuse of prescription drugs along with allegations of drunkenness, breaching curfews, deceit and bullying were highlighted in a review published on Tuesday, which said slack management had allowed a "toxic" culture to develop in the team.

Roberts said he personally had never taken Stilnox.

The relay squad arrived in London confident of winning gold but ended up fourth in the final as the swimming team produced Australia's worst results in the Olympic pool for two decades.

"As a senior member of the team I should've stood up and took more leadership at the time," said Sullivan.

"If I thought for one moment that these actions and our communal decisions to take Stilnox would affect our performance, there's no way I would've done it. And I believe there's no way it would've affected our performance at all."

($1 = 0.9754 Australian dollars)