The New Zealand Initiative will commission an independent investigation of its content after a sub-editor was found to have authored a blog with anti-Semitic, Islamophobic views.
Nathan Smith, who worked as Chief Editor at the free-market economic thinktank, was initially on leave pending the outcome of an investigation.
NZI executive director Oliver Hartwich said Smith had resigned shortly before midday today after the blog's abhorrent content - which included a claim that the extent of the Covid-19 pandemic has been exaggerated - came to light.
He told Midday Report that Smith had mostly subedited others' work, and he was confident there were no people who held similar views.
"I'm very confident about that because we talked with staff this morning and we were all shocked to find these views because they are simply not the views of the initiative.
"We were very shocked ot find them yesterday and we had absolutely no knowledge of it."
He said Smith's resignation came after a brief conversation.
"It was a brief phone call where he explained that he's resigning within the notice period followed up by the extended resignation email, and I've accepted that."
"He's no longer working here, he has now resigned, and no longer works for us,"
He said it was not publicity anybody would like to have.
"These views exposed on this anonymous blog are diametrically opposed to what we stand for. The initiative's been going for almost nine years now and our views are very clear that we want to see a better New Zealand for all New Zealanders regardless of race."
He said there had been no indication that Smith held the views professed in the blog.
"None whatsoever, and in fact I would go further because before he started with us he was already in the public domain, if you like, as a journalist for the National Business Review for seven years.
"That's in fact how I met him because he interviewed me when he was a journalist ... his public writing in the paper was very good and didn't expose any of these views which is why it's come as such a shock to us.
"His published opinions and his public personality with the NBR as a journalist is so different from what we discovered only yesterday."
In a statement, Hartwich said Smith had joined the think tank this year from the National Business Review, where he had worked as a journalist for seven years.
"The statements he had made are diametrically opposed to the Initiative's views," Hartwich said.
"As concrete examples, our work on immigration has advocated a more open approach, enabling more migration from all parts of the world. We have been and continue to be advocates of enabling New Zealand to accept more refugees.
"Nathan had mainly worked subediting our writing. These edits are always checked by the respective authors and signed off by me before publication. Nevertheless, we will have an independent investigation to examine whether any of our material had been compromised."
"The Initiative's views have been the same since we started in 2012. Our mission is to help create a competitive, open and dynamic economy and a free, prosperous, fair, and cohesive society."