UPDATE: IMMENSE pressure and the need to "be normal for one night" fuelled a team bonding session where swimmers took sedatives and played childish pranks on team members before the London Olympics, James Magnussen told reporters on Friday.
The admission followed an announcement from Swimming Australia that Magnussen and five of his 4x100m relay members - Eamon Sullivan, Tommaso D'Orsogna, James Roberts, Matt Targett and Cameron McEvoy - would be investigated by its integrity panel over the latest sports scandal to rock the nation's athletes.
In a statement read out by Australian Swimmers Association Daniel Kowalski on behalf of the squad, swimmers admitted to taking the sedative Stilnox with the knowledge it had recently been prohibited by the Australian Olympic Committee.
They claimed to have participated in what they thought was "harmless fun", where they "sat around the hotel room telling stories, laughing, bonding, just as we had wanted to do".
It was conceded that at some point, "some team members left the room and decided to make prank calls to random rooms and did knock on the doors of some of our team mates but at no time did we ever feel it was anything more than childish behaviour and there was definitely nothing untoward in our actions".
The team maintained it was "honouring tradition" but accepted it was childish and took responsibility for the members who had originally denied the incident took place.
"We have chosen to announce this today as together we want to put this incident behind us," the statement read.
"A lot has been written, speculated and talked about with regards to this incident - we own up to it, we take responsibility for it and are deeply sorry for it."
Apologising for his "ridiculous" behaviour Magnussen said while the pressure he was under had been building "for the best part of a year" and the chance to bond was appealing, he had a "lot of regrets".
But he denied the Stilnox affected his performance in the pool and dismissed reports he and Targett had bullied a younger male team member as "completely false".
The pills were prescribed to Sullivan and Targett and filled in Australia before the team stayed at the Manchester training camp.
Sullivan told the conference Stilnox was a substance commonly used in racing and something he had often taken to prepare for early starts.
James Robertson maintained on Friday he had "never taken Stilnox in my life", but admitted being part of the night's antics.
All other team members said they had taken one tablet.
According to Swimming Australia, the six members could be fined and/or handed a letter of warning depending on the outcome of the inquiry.
The integrity panel was set up earlier this week following the release of a scathing review which found a "toxic culture" of bullying, drinking and misuse of prescription drugs contributed to the poor performance of Australia's swimming team in London.
Australia's swimming shame deepens with new revelations
MEMBERS of the men's 4 x 100-metre relay team are expected to face the media today to admit to damning behaviour which is expected put a blowtorch on Australian swimming's toxic culture.
James Magnussen, Eamon Sullivan, James Roberts, Matt Targett, Cameron McEvoy and Tommaso D'Orsogna will front a press conference at which they are expected to reveal explosive details about their behaviour, including the use of prescription drugs, in the lead-up to the London Games.
Fellow Olympian Jade Neilsen has spoken out ahead of that press conference, detailing her teammates' ''inappropriate behaviour''.
Neilsen said she and an unnamed roommate were woken by late-night phone calls and door-knocking from James Magnussen, James Roberts and Cameron McEvoy while at a team staging camp in Manchester.
Neilsen said she and her roommate told coaches of the men's strange behaviour, but were ignored.
''I will confirm they were being inappropriate and it was towards [unnamed roommate] and I. I won't specifically say [what happened],'' she told News Limited.
''It has sort of already come out, pretty much, what they've done. All I can say is their behaviour was completely inappropriate. It was so inappropriate it was not funny. That is all I can really say about that.''
News Limited reported that Magnussen barged into Neilsen's room with McEvoy, both wearing only jeans.
Later, McEvoy reportedly returned with Roberts, who was wearing only underwear, and started banging on the doo
The revelations come after a report detailed a "toxic culture" of bullying, binge drinking, prescription drug use, breaking team curfews and deceit by some of Australia's Olympic swimmers went unchecked during the London Games.
This, and a number of other "cultural factors", was found by the Bluestone Review to have contributed to poor results and an "unpleasant" experience for many of Australia's swimmers, coaches and staff in London.
Australia won 10 swimming medals overall, including six silver and three bronze - the country's worst performance in 20 years.
The subsequent review found any sense of team among the Australian swimmers broke down as the focus switched more to individuals in the lead-up to, and during, the event.
A "candy shop of distractions" inside the athletes' village also added to the lack of team cohesion.
Some swimmers described their London experience as the "Lonely" and "Individual" Olympics.
"Swimmers seemed to have missed the power of a shared experience, and critically, of friendship. In simplest terms this meant it was a lot less enjoyable than they expected," the report released yesterday read.
"It is plausible that emotional tension in the group built to disharmony and sometimes became exclusion and, in the rare extreme, animosity between athletes."
A focus on the "best" swimmers within the team also added to tension within the team, the review found.
Some of the review's most damning findings centred on bullying within the team, with some individual acts of "unkindness, peer intimidation, hazing and just bad form" going unpunished.
The review also found the team suffered from a lack of authority.
"(This) occasionally peaked in a mood where the boldest took centre stage. At its least attractive, the team dynamic became like a schoolyard clamour for attention and influence," the report read.
In terms of a lack of discipline, the review found "situations were left to bleed ... for fear of disrupting preparation for competition".
Australia took one of its youngest swimming squads to London - 24 of the 47-member team were first-time Olympians. The review found there was not enough induction for these athletes.
Further, the review was critical of Swimming Australia's failure to dampen expectations.
"In the absence of a leadership voice from Swimming Australia ... the media reported, even bolstered, expectations of the medal haul and overshot the mark."