A former partner of Derek Fox said she had to defend herself in a "fist-fight" against the Maori Party hopeful but never needed hospital treatment.
A Truth article claimed this week that one woman was "hospitalised" as a result of Mr Fox's "unsavoury" behaviour.
In response, Mr Fox said he had done things in his past he regretted, but had spent years since trying to contribute positively to society.
"I surrendered myself to the authorities, I sought help to address those issues, and I believe I am a very different person now."
The ex-partner, who asked not to be named, said a fight between the pair ended their relationship 15 years ago. She said rumours that she had been hospitalised were untrue.
"I was defending myself. I've grown up with sisters, brothers, cousins, uncles who are a pretty tough lot.
"If you want to defend yourself, you fight dirty, that's how I was raised. Any bastard that comes at me, he's going to get it.
"That's what happened: we had a full-on fist fight. He's bigger and won."
She said she believed their history would become public and had asked Mr Fox not to stand for Parliament in 1999, when he was an independent, and again this year, to protect her wider family.
However, she had mixed feelings about the incident coming into the public arena. "I had hoped he would face up to this in public.
"There's a certain amount of relief. But I saw the story on TV and I went, 'Oh no'."
Yesterday, Mr Fox refused to comment, saying he did not want to add further to earlier statements.
Meanwhile, both Maori Party co-leaders are standing behind Mr Fox.
Tariana Turia said the party was made aware of allegations when Mr Fox raised the possibility of becoming a candidate.
"He'd said there had been issues in his life, that he believed he'd dealt with them and that he'd had counselling. I don't have any reason to doubt anything he said."
Mrs Turia, who has worked with men with anger issues, said there were always chances for redemption, but that didn't mean the party was excusing any of his behaviour.
"I'm totally intolerant of violence, I don't mind telling you that, but I also believe that the way to stop violence is to support [people] to get the right help and then to support them after, and that's what the party intends to do."
The other co-leader, Pita Sharples, said Mr Fox's contribution to broadcasting and print journalism as well as being Wairoa mayor in the intervening years shouldn't be forgotten.
"The thing is, it happened a long time ago. He offered an unqualified apology, no excuses. He's satisfied us that he's done the right thing since he did the wrong thing."