The 32-year-old, who won the 100m freestyle world titles in 2011 and 2013, plans to come out of retirement and compete in the "Enhanced Games", where banned substances will be allowed. He has also won three Olympic medals (a bronze at Rio 2016 and a silver and a bronze at London 2012), as well as a gold in the 4x100 freestyle at the 2013 World Championships in Barcelona and a gold in the 4x100 freestyle at the 2014 Pan Pacific Games. 

The 2023 Games, founded by London-based Australian businessman Aron D'Souza, would not be subject to World Anti-Doping Agency rules - a concept that has been criticised as dangerous. According to the Games website, all participating athletes will receive a base salary and prize money that will be "larger than any other comparable event in history". 

Those who break a world record would receive $1 million, with Magnussen, who retired in 2018, the first big name to take the bait of breaking the 50m freestyle mark. If he did so, it would not be officially recognised. 

"If someone had asked me to do this during my swimming career, my answer would have been very different, but today I have been out of the sport for six years. The money is a big part of it. AU$1.6 million (€967,000) is hard to ignore. Retired athletes don't get opportunities like this," the Oceanic admitted to an Australian newspaper. 

Brazilian Cesar Cielo has held the 50 m freestyle world record (20.91) seconds since 2009, when he set it in a high-tech 'supersuit' that was later banned. Magnussen has a personal best of 21.52, set at the 2013 EnergyAustralia Swimming. He is fourth on the Australian list behind national record holder Mcameron McEvon (21.06), Ashley Callus (21.19) and Eamon Sullivan (21.28).

He would not take any risks with his health. "I want to be surrounded by the right medical support to be sure that any supplements will not have a negative long-term effect on my body. This is not for everyone, and certainly not for young athletes, but if you can seriously improve performance scientifically and safely, it could be an entertaining event for people to watch," said Magnussen. 

Backed by venture capitalists, the Games will include athletics, aquatics, gymnastics, strength and combat. A date and venue for the inaugural edition of the Games have yet to be announced. "It is time to pay the athletes and reward excellence. People like James deserve to earn millions for the extraordinary things they have achieved," D'Souza said on social media platform X. 

Since the Enhanced Games concept was introduced last year, the reaction from the sporting world has been negative. The Australian Olympic Committee has called the idea "dangerous and irresponsible". "Why would we want to know who can cheat the most to win prizes?," asked former English swimmer Sharron Davies, an Olympic silver medallist, on social media.