Duncan Garner has been getting unsolicited offers from members of Ashley Madison - but the TV3 presenter says he never signed up to the site.
Garner, the host of TV3's new 7pm current affairs show Story, says someone else signed him up to the service, which runs under the motto, "Life is short. Have an affair."
Ashley Madison has hit headlines over the past week after the website was hacked and up personal data of its 37 million members - including celebrities - was leaked.
Garner, who is "happily married," says he has no idea how he ended up on the site.
TV3 reported he had been getting emails from married strangers wanting to meet up.
"I actually don't know how they got it, I don't know how I appeared on their list, I don't know who signed me up or how I've been signed up, I have no idea whatsoever," he said.
"I'm married, happily married, I don't need Isabella or Cocomama, I don't need that coming at me to be honest."
In a recent column, Garner said he'd had "two genuine offers".
"Kokomama, a 57kg Asian woman, 21, sent me a message wanting 'something long term' ... Suzy, 28, is a married, 100kg, 'white' woman who reckons 'anything goes'," he wrote.
Garner also admitted joining Tinder - but says it was research for a piece on his radio show.
"I had 10 potential dates within an hour. One woman was pretty keen. So was some guy," he wrote.
Read more: Married Duncan Garner spotted on Tinder
Ashley Madison is offering a US$500,000 reward for information leading to the arrest of the group that hacked its site and released detailed records of as many as 32 million users.
"This hack is one of the largest data breaches in the world and is very unique on its own in that it exposed tens of millions of people's personal information including their credit card data," said Bryce Evans, staff superintendent with the Toronto police.
"This is affecting all of us. The social impact behind this leak, we're talking about families, we're talking about children, we are talking about wives, their male partners."
Mr Evans said the police had received two "unconfirmed reports" of suicides associated to the leak".
US reality TV star Josh Duggar was one of the celebrities named and admitted being unfaithful to his wife over the course of their marriage.
Duggar said: "I have been the biggest hypocrite ever. While espousing faith and family values, I have secretly over the last several years been viewing pornography on the internet and this became a secret addiction and I became unfaithful to my wife."