Australian Olympic swimmer Ian Thorpe has come out gay.

The 31-year-old Thorpe announced for the first time publicly that he's gay during an interview with Sir Michael Parkinson broadcast Sunday night on Australian's Channel TEN.

“I've thought about this for a long time. I'm not straight,” Thorpe answered when asked about his sexuality. “And this is only something that very recently, we're talking in the past two weeks, I've been comfortable telling the closest people around me exactly that.”

Thorpe has won five Olympic gold medals, the most won by any Australian. He was also the most successful athlete to compete at the 2000 Summer Olympics.

Thorpe denied rumors he's gay in his 2012 autobiography This Is Me.

“For the record, I am not gay and all my sexual experiences have been straight. I'm attracted to women, I love children and aspire to have a family one day … I know what it's like to grow up and be told what your sexuality is, then realising that it's not the full reality. I was accused of being gay before I knew who I was,” he wrote.

He said Sunday that he “lied” because he didn't want his integrity questioned.

“And, you know, a little bit of ego comes into this. I didn’t want people to question that. … Have I lied about everything?”

“I've wanted to [come out] for some time. I didn't feel I could. Part of me didn't know if Australia wanted its champion to be gay.”

“I'm comfortable saying I'm a gay man,” Thorpe said. “And I don't want young people to feel the same way that I did. You can grow up, you can be comfortable and you can be gay.”

He added that he was concerned about how his family would react to the news.

“I'm pleased to say that in telling them, and especially my parents, they told me that they love me and they support me. And for young people out there, know that that's usually what the answer is,” he added.