Nick Willis says help from his wife, Sierra, has helped him beat his porn addiction.

New Zealand Olympic 1500m star Nick Willis says breaking the silence over his pornography addiction is worth it if it helps one person succeed in their own battle.

Willis revealed a secret and long-running addiction to pornography that he feels is now under control, the 32-year-old taking to Facebook as he marked two-and-a-half years being porn-free.

The admission has created a stir, with Willis on Sunday suggesting he was surprised by the media interest in his initial post.

"I guess I never realised how much interest the media would have in my Facebook post," Willis wrote on his Facebook page on Sunday, "but I want to affirm that breaking the silence is worth it if even only one person succeeds in winning his/her battle".

The candid admission blindsided Athletics New Zealand chief executive Linda Hamersley, but she accepted the Olympian publicising his plight - and rehabilitation.

Hamersley, who is in Dunedin at the New Zealand Track and Field Championships, learned of Willis's revelation on Sunday and felt it would not impact on the organisation, or the sport's reputation.

"Our position is it's a personal issue that Nick has raised. We don't really have an opinion on it.

"It's something he obviously felt strongly that he needed to reach out and let people know. It is a personal matter."

Hamersley, who has been in the role for 18 months, said she did not know Willis well because he spends the bulk of his time in the United States or competing internationally.

"My initial reaction was "Oh." I wouldn't personally put that on social media but I'm not of the era that put personal issues on social media," she said.

"It's something very personal to Nick and his family, and he's chosen to share it."

Willis has battled the addiction since he was a lonely teenager but only in more recent years he came to realise the implications the addiction had on his life.

I guess I never realised how much interest the media would have in my Facebook post, but I want to affirm that breaking the silence is worth it if even only one person succeeds in winning his/her battle. Posted by Nick Willis on Saturday, March 5, 2016

"I am 2.5 years porn free (and it feels AMAZING)," Willis, a proud Christian, posted on his Facebook page on Friday.

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"Since I was a teenager, it had been a rollercoaster ride of shame and justification as I was on and off with this addiction. Not until I realized the true implications this had on my marriage, and ability to father could I finally break free."

Willis linked his post to an article titled 'What it means to be pro-sex and anti-porn' on a website called fightthenewdrug.org, referencing it in his post.

"Porn makes you think you are having sexual needs met, but really they are hollow and leave you feeling empty and lonelier than before. Basically, pornography is a very unnatural (and very temporary) solution that people use to satisfy a natural desire.

"Pornography will not and cannot love you back."

"Porn makes you think you are having sexual needs met, but really they are hollow and leave you feeling empty and... Posted by Nick Willis on Thursday, 3 March 2016

Willis, who won a silver medal at the 2008 Beijing Olympics, was the New Zealand flagbearer at the London Olympics in 2012 and will line up in Rio in August this year, credited his wife, Sierra, for helping to beat his dependence.

He said opening up to her and the hurt it caused was something he never wanted to make her experience again.

"Before I focused on how my addiction affected me, but it wasn't until I realised the affect it had on others, especially my wife that I committed to change," the 2006 Commonwealth 1500m champion told NZME.

"Sierra showed a great amount of grace with me. We decided to beat it together. We talked openly about the issues of sex trafficking, abuse of women, objectification of women and accessibility of pornography for young people on cell phones.

"Getting this topic out of my secret life out into the open, and talking, talking, talking has been the biggest impact in breaking the cycle."

Willis lives in Michigan with his wife and 2-year-old son, Lachlan.