Wallace, the only Australian to have won a medal in gymnastics (silver on the trampoline in Sydney), said he walked around for weeks in a haze of shock and disbelief after learning a year ago he had contracted the virus from his partner at the time.

But Wallace says he has never looked back since that difficult couple of months he spent alone in Canada grappling with his new reality. Which is why he went public this week, inspired by an interview with Greg Louganis, the four-time Olympic diving gold medallist who revealed he was gay and HIV positive in an autobiography in 1995.

“I was in London at the Games and watched Piers Morgan interviewing [Louganis] and it was just such a normal interview and so positive,” Wallace said in Sydney after flying home from his role as an ambassador for the Federation of Gay Games.

“I felt like he had come a long way because when Greg came out it was a shock-horror story, quite negative, and it was really nice for him to sit there openly [this week] and talk about it. That night I had trouble sleeping so I wrote to Piers Morgan and said, ‘Thanks for treating him well … it’s a big issue and it always will be but you didn’t sensationalise anything.’ I wanted to say thanks and that I too was an Olympian living with HIV.”

The letter, which Wallace also sent to the Sydney Star Observer, a weekly newspaper for the gay, lesbian, bisexual and transgender community, went viral on the internet and resulted in “literally thousands” of messages of support and gratitude for Wallace.

“It’s not a big deal to me. Everybody I needed to tell was very supportive of me, but it is a big deal to those people who find themselves discriminated against or bullied because of it,” he said.

“If one or two people or thousands of people get encouragement and courage to chase their dreams or live their lives honestly, if what I wrote makes a difference, then I have done the right thing.”

Wallace was openly but not publicly gay in Sydney when, as a long shot, he delighted a thunderous home crowd with a silver medal at trampolining’s Olympic debut. He made his sexuality known publicly four years later when a friend convinced him gay athletes should talk more about their sexuality. Life continued as normal, punctuated by a move to Canada to work with Cirque du Soleil, before his life changed last year.

“When a partner tells you they have HIV you’re super concerned about them, but then it was, ‘Hold on, if you have it does that mean I have it?”‘ Wallace said.

“Until I got tested there was that part of me that was ‘It’s a dream, it’s a dream’, unless it’s happening directly to you, you don’t really educate yourself about it … and then it seems like a bomb goes off in your head. And because I was overseas I wandered around like a zombie for a little while. It was quite some time before it really sunk in.”

Wallace moved back to Australia and began a program of antiretroviral drugs after being told he was “too healthy” to take part in trials for new drugs. He has his first big check-up next week but said by far the toughest challenge of the past year was telling his parents.

“Because they’re a generation and a half behind me, my parents are not within my community or current information system. I was really quite scared to tell them because I didn’t want them to think their son was going to die this horrible death,” he said.

Wallace took both parents to his doctor and watched, relieved, as “the fear drained out of their faces”.

“That’s another reason why I’m [speaking out],” he said. “I’m doing this to re-educate people about what it is and what it means to live with it.”