Olympic swimming legend and Australian Sports Commission boss Kieren Perkins has warned that "someone will die" if a multi-sport event that allows athletes to use banned substances goes ahead.
The Enhanced Games have been proposed by Australian entrepreneur Aron D'Souza, with Australia's dual world champion swimmer and triple Olympic medallist James Magnussen the first athlete in the world to publicly pledge to compete at the 2025 event.
D'Souza has promised the retired Magnussen $1.54 million if he can break the world 50m freestyle record.
Speaking at the SportNXT conference in Melbourne, Perkins described the event as "borderline criminal".
"Someone will die if we allow that sort of environment to continue to foster and flourish," the two-time Olympic 1500m freestyle gold medallist told the conference.
Perkins expanded on his stance to AAP, saying doping is banned for the safety of athletes, and that should not change.
"Performance-enhancing drugs have always been utilised and designed in a way to try to get an advantage that the human body is not built for, and it always leads to disaster," he said.
"The idea that you can just manage it in a vacuum is really quite silly.
"There is a litany of historical figures in sport who have ended up dying from being involved in taking performance-enhancing drugs, and it's the reason why it's illegal and should always remain that way."
While not commenting directly on Magnussen, Perkins said sport shouldn't turn its back on athletes contemplating taking part, and they should be "protected from making poor decisions".
"I certainly fear for them (athletes), and it's disappointing because of the selfishness that's involved," he told AAP.
"There's plenty of historical examples of athletes that don't survive through their forties because of taking drugs, whose children are severely disabled, malformed and have had short lives themselves.
"The impact isn't just on the individual, the impact is on potential generations, so there's a high level of ignorance and selfishness that comes with it.
"Giving people the opportunity to be informed and understand what the risk is that they're taking is a starting point, but it isn't something that we should walk away from and say 'If they want to go kill themselves, knock themselves out'.
"I don't think civil society has been comfortable with that context for a long time."
Perkins said questions should be asked about the commercial objectives of the organisers and pharmaceutical companies involved.
"What's the end game here? I'm willing to bet that the end game is not something that's better for individual athletes and society at large," he said.
Swimming and diving are among the disciplines on the Enhanced Games schedule, along with track-and-field athletics, weightlifting, gymnastics and combat sports.
D'Souza is in negotiations with global television networks and streaming outlets, while venues around the world are pitching to host the Games.
Up to seven qualifying events will be staged this December around the world, including Australia, with the inaugural Games slated for the middle of next year.
