Deputy Prime Minister Winston Peters has denied Dame Susan Devoy's claim than he once suggested she was overweight, saying "her memory is failing her".
But another account from 2011 seems to corroborate the story.
The former squash champion made the comments at a sports journalism awards function in Auckland on Thursday night.
Dame Susan, the Race Relations Commissioner, recounted an event from 1987 where Mr Peters was "his usual obnoxious self".
She said Mr Peters gave a speech in which he described her as being "a bit on the round side" and probably in need of a long walk.
"I'll never forget it," she told the crowd.
Speaking to reporters on Friday, Mr Peters disputed the anecdote.
"I said she was an exceptional spokesperson because she could win when she wasn't fit - against the best in the world."
Asked why he thought Dame Susan was not fit, he said it was "patently obvious".
He said he meant his comments as a "compliment" and "common sporting parlance".
"I've seen it be made of rugby players ... Look, that person's not fit, but he's still so good that even at 70 percent he's better on the paddock than others going at 100."
Mr Peters said he had no recollection of saying Dame Susan was overweight. He also queried the timeline, saying it happened years before Dame Susan walked the length of the country in 1988.
Dame Susan has declined RNZ's requests for an interview.
A 2011 Stuff article recounted the same events, placing both Mr Peters and Dame Susan at a sports journalists' prizegiving "in the late 1980s".
Sports reporter Phil Gifford wrote that Mr Peters told Dame Susan:
"I have always admired enormously the fact you can win world titles while carrying so much extra weight."
Dame Susan later asked Mr Peters if he had meant what he said.
"Yes, he had," Mr Gifford wrote. "He saw it as a compliment to her fighting spirit."
Dame Susan and Mr Peters have clashed several times before.
In 2014, she condemned a 'joke' by the NZ First leader as "extraordinarily offensive" and "outdated rhetoric".
More recently, Dame Susan chastened Mr Peters after he described a NZ Herald report written by Asian reporters as propaganda.
"Debate facts," she said.