A member of Viktor Orban's inner circle has resigned after the Hungarian prime minister spoke out against becoming a "mixed race".

Zsuzsa Hegedus, who has known the nationalist Mr Orban for 20 years, described the speech as a "pure Nazi text", according to Hungarian media.

The International Auschwitz Committee of Holocaust survivors called the speech "stupid and dangerous".

Mr Orban's spokesman said the media had misrepresented the comments.

The speech took place on Saturday in a region of Romania which has a large Hungarian community.

In it, Mr Orban said European peoples should be free to mix with one another, but that mixing with non-Europeans created a "mixed-race world".

"We are willing to mix with one another, but we do not want to become peoples of mixed-race," he said.

Mr Orban's anti-migration views are well known, but for Ms Hegedus Saturday's speech crossed a line.

"I don't know how you didn't notice that the speech you delivered is a purely Nazi diatribe worthy of Joseph Goebbels," she wrote in her resignation letter, according to the Hungarian hvg.hu news website.

Goebbels was the head of Adolf Hitler's propaganda ministry.

Hungary's largest Jewish group also condemned the speech and called for a meeting with Mr Orban.

Mr Orban's remarks on race have been bitterly criticised by some in Hungary, and equally vehemently defended by others.

"Only one race inhabits this earth, Homo Sapiens. And it is unique and undivided," chief rabbi Robert Fröhlich commented.

Opposition politicians, decisively defeated by Mr Orban's Fidesz party in the April elections, said his remarks were "beyond the pale... unworthy of a European statesman".

Government spokesman Zoltan Kovacs tried to dampen the growing chorus of condemnation, arguing that the prime minister had been outspoken on the topics of immigration and assimilation for years.

In the government flagship daily, Magyar Nemzet, an article praised Mr Orban for defending the idea of nationhood against a drive to mix all nations "into a grey, indistinguishable mass".

At best, Mr Orban appears confused, sometimes speaking of the Hungarians as "the most mixed society", at other times, appearing to suggest he believes in ethnic purity.

Zsuzsa Hegedus's resignation is unlikely to have further repercussions in Hungary. Party discipline is tight, and resignations almost unheard of.