Ian Thorpe is Australia's greatest Olympian, winning nine medals, including five gold, during his career, and yesterday in an interview with Austrailia's Ten News, he also revealed that he was gay. 

Thorpe, 31, revealed in a paid interview on television at the weekend that he was gay, saying the stress of "trying to live a lie" had contributed to his depression.

"I'm ashamed I didn't come out earlier because I didn't have the courage to do it," he said."I didn't know if Australia wanted its champion to be gay."

Thorpe's father Ken said on Monday his son's revelation was "a shock"."We never had any indication Ian was that way inclined," he told Channel 7, "God loves Ian and we love Ian unconditionally and we'll support him."

"It was the best week that we've had with him and even his friends have made the same sort of comments, that he's been really good to be around," Mr Thorpe said.

American champion Mark Spitz, who won seven gold medals at the 1972 Olympics, said Thorpe's performances in the pool might have been weighed down by the burden of keeping his sexuality secret.

"You can imagine the emotional things that he had to go through over the years to suppress that," Spitz said.

"If he didn't have to do that what would his records have been? If he didn't have to worry about things like that he may have been more focused. To me, it could only have been a more positive experience."

Thorpe's emotional turmoil was such that he retired from swimming prematurely, in 2006, said long-time mentor and sports psychologist Deidre Anderson.

"He probably would have been able to continue swimming, I have got no doubt in my mind," she said.

"Any time you can't invest absolutely every part of yourself both psychologically and physiologically at the level these guys compete at, it's got to have an impact."

Thorpe, who returned briefly to swimming in 2011, revealed he was gay to his closest family and friends, including Anderson, about a month ago.

"I think it's all part of him getting to a point in his life where he has been able to reflect on who he is and how he wants to live his life," she said, "He has been living everybody else's life for so long, I think it is a wonderful step towards finding some happiness."

Thorpe said he did not want young people to feel the same way he had, saying the "lie had become so big that I didn't want people to question my integrity". 

Thorpe delayed his decision to come out, in part, because of concerns over how the revelation might affect his family, Anderson said. Thorpe contemplated coming out as gay before the 2000 Sydney Olympics, but decided against it, in part because of the prospect of losing lucrative sponsorship and marketing deals.

Thorpe went on to become one of the highest-priced athletes in Australia, with multimillion-dollar deals with companies such as Qantas, Omega and Telstra.

"In 2000, financially it may have been more difficult for him to come out," said celebrity agent Max Markson, "But I think the public today and corporates today are much more accepting of a sport star coming out."

Thorpe's decision to come out publicly now would only improve his marketability, Markson said.

"For the last year or so he has been this mysterious figure with injuries and depression... and now we have seen him unveiling his life and moving on from that. It is a fresh start for him."

Thorpe said during the interview that he hoped to further his television career. Whether he might have achieved more swimming success is pure speculation, Spitz said. Thorpe's emotional toil might have even driven him to sporting glory, he said.

"It may have been the reason why he was so good, that the pain he suffered was channelled into becoming one of the best athletes in the world,'' he said.

"Only he would know how heavy that burden was for him over the years."

Openly gay superstar Ricky Martin is believed to have been instrumental in swimmer Ian Thorpe's decision to 'come out'.

Father-of-two Ricky who is in Melbourne to promote a new series of The Voice has refused to confirm or deny the rumours. Respecting his pal's privacy he simply stated his joy for the Olympic gold medallist in finding the courage to tell the world the truth.

He said: "I am extremely happy that he is talking about his happiness and that is where I would like to leave it."

Ricky even took to Twitter to express his support and admiration for Ian, who finally revealed he is gay on Australian TV on Sunday.

He wrote: "Congrats @IanThorpe! Brave man! Happy for you! Millions appreciate what you've done! Proud of you! #SelfLove".

After the interview, swimming star Ian - known affectionately as the Thorpedo - was inundated with messages of support from the sporting and entertainment world, as well as the gay community world-wide.

Fans and supporters worldwide have inundated Ian with messages of support since the interview revelations.

Thanking everyone for their kind words, Ian said: "To everyone who has sent a message of support I sincerely thank you!"