Matthew Mitcham has revealed how he struggled to come to terms with his sexuality and even went so far as to train himself to not be gay. 

Mitcham, 35, made the shock confession during his interrogation on SAS Australia by Anthony Middleton on Tuesday night's episode. 

The Olympic diver, who became the first openly gay athlete to win gold after his triumph at the 2008 Games, said he tried to suppress his sexuality from a young age.  

'I was the only child in a single parent household and obviously [my mums] life was difficult so the easiest way to make me be as easy as possible was to control me through fear.

'I knew from five I liked boys. Through primary school and religion, shame started getting put onto it. 

'So then I put a rubber band around my wrist because I knew being gay was such a bad thing.

'Every time I had a bad thought I would snap the rubber band against my wrist to try to associate pain with it to try to train myself out of being gay'

Mitcham added that his feelings of guilt culminated in him attempting to take his own life. 

'When I got overwhelmed with feelings I got on the inside I used to cut myself,' he said. 'After one particular episode I went to far and I had to call my grandma to take my to hospital.'

Mitcham has previously spoken of his battle with alcohol and meth as he struggled to cope with a 'post-Games comedown' following the 2008 Olympics in Beijing.

After his triumph in Beijing, he developed a dependency on the drug ice when he discovered he was not world No. 1 in the global rankings, despite his Olympic success.

Incredibly, the diver felt like a failure and soon found himself training and competing while juggling a crippling drug addiction.

'Knowing I would be drug-tested at every competition I would detox [from drugs] for the weeks before competing and I'd go through these horrible withdrawals,' he told the BBC.

'They were so bad that I'd promise myself with every cell in my body that I was not going to use again, but I couldn't ever keep the promise.

'It got dark. My self-esteem was shattered, at times killing myself seemed like the easiest way to deal with this, but I finally took myself to rehab.'

In January, Mitcham celebrated seven years of sobriety after his addiction to crystal meth and alcohol almost ended his career.

He announced the milestone achievement on Instagram, saying he was 'the happiest and healthiest I've ever been'.

'Today I am SEVEN YEARS clean and sober,' Mitcham wrote.

'It has been seven years since I put anything stronger than a Panadol in my body, and I am without a shred of doubt the happiest and healthiest I have ever been.'