Barnaby Joyce says he was wrong to dismiss concerns of Nazism within the National Party just hours after likening an investigation into the matter to a McCarthyist witch hunt.
"I take it all back," Mr Joyce told AAP.
The former deputy prime minister earlier on Friday said he was skeptical of whether a neo-Nazi infiltration of the NSW Nationals had occurred.
"Who is the Nazi? Who is it? ... Sorry for my aggression but I am cynical of this shit," Mr Joyce told AAP.
"I've seen Prince Harry in a Nazi uniform, I'm pretty certain he's not a Nazi.
"I have an inherent cynicism because of a knowledge of how politics goes, right back to the McCarthyist witch hunts for the reds under the bed."
But within two hours, Mr Joyce said he'd made a call and agreed there was a problem.
"These guys are crazy," he said.
"(They should) have no role in our party whatsoever."
Almost 20 NSW Nationals members have quit the party amid an investigation into their alleged connection to alt-right and white supremacist organisations.
The NSW Nationals on Friday vowed to "not rest" until all suspected neo-Nazis were weeded out and passed a motion ruling membership with a host of alt-right organisations was incompatible with the party.
Earlier in the day Mr Joyce said there had been a rise in factionalism within his party in recent years and the allegations of Nazism could just be a factional war.
"Factions are a very poor replacement for policy," he said.
"The person on the left is apparently a communist or a socialist ... and everyone on the right is a fascist."
However, Mr Joyce said if it were proven any Nazi sympathisers were working within the party, he wanted them out.
"If you know of a Nazi, give me the name and give me substantial evidence," he said.
"If someone has done something wrong, if they've broken the law, sure, if they were fair dinkum a member of the bloody Nazi Party then you won't have to wait for anyone else to get to them. I'm a former serving member of the defence force."
Mr Joyce said the scandal would almost certainly damage the Nationals in the looming state and federal elections.
"This ain't helping our electoral prospects."
"Any decision I make will be premised on real evidence and real names."
He later said no Nazis had ever made themselves known to him.
"For the life of me, I've never met someone who presented themselves to me as a Nazi but maybe they thought it was a wise thing not to."
A dossier, seen by AAP, contains information about several party members and their links to the white supremacist or neo-Nazi movement, including screenshots of the alleged ringleader organising their memberships.
Australian Associated Press