Thorpe has long faced questions about his sexual orientation and has frequently denied being gay, saying his relationships have been with women.

But speaking to Parkinson on Channel 10, he admitted the actual story is a different one.

“I’ve thought about this for a long time. I’m not straight,” he said. “And this is only something that very recently – in the past two weeks – I’ve been comfortable telling the closest people around me exactly that.

“I don’t want young people to feel the same way I did. I’ve wanted to for some time. I couldn’t, I didn’t feel as though I could.

“The problem was I was asked at such a young age about my sexuality. I went to an all-boys school, so if you’re accused of being gay then the first answer is no and you get ready for a fight.

“I didn’t know at the stage, I was too young. I carried this. I thought that the lie had become so big that I didn’t want people to question my integrity. A little bit of ego comes into this. I didn’t want people to question whether I’d lied about everything.

“Yes, I lied about it. I’m comfortable saying I’m a gay man. My parents told me that they love me and that they support me. Part of me didn’t know if Australia wanted its champion to be gay. But I’m telling the world that I am.”

Known as ’The Thorpedo’, he won five Olympic golds in a stellar career which he tried to revive having initially retired in November 2006.

Keen to add to his medal haul – which also included 11 World Championship golds - Thorpe has made aborted attempts to return to the pool ahead of the 2012 Olympics, last year’s World Championships and this month’s Commonwealth Games.

Thorpe’s personal life has been more prominent than his professional one over recent years.

In his 2011 autobiography, ’This is me’, he wrote of a battle with depression and his reliance on alcohol. He added to Parkinson that only the love of his family had stopped him committing suicide.