The Holocaust-denying historian David Irving has sparked anger by organising £2,000 (NZ$4,830) tours of concentration camps.
The disgraced academic has been accused by Holocaust memorial groups of insulting the memory of those killed in the Second World War by spreading 'pro-Nazi propaganda' on the tours.
Irving, 77, is notorious for his attempts to play down the extent of the Holocaust, and his insistence that Hitler was unaware of the plan to exterminate the Jews.
He was publicly exposed after his failed bid to sue author Deborah Lipstadt for calling him a Holocaust denier. Next month, Irving is to take a group of "international guests" to Poland, where they will visit four concentration camps at Treblinka, Sobibor, Belzec and Majdanek.
They will also stop at the ruined "Wolf's Lair", the fortress near the town of Ketrzyn built to be Hitler's headquarters on the Eastern Front.