The probe also found retailers were advertising books by some of the most extreme and dangerous neo-Nazis including pro-National Socialism works by the now-deceased leader of the World Union of National Socialists, Colin Jordan, on online stores.
Extreme far-right books available included those by Holocaust deniers such as David Irving, Nick Kollerstrom, Italy’s leading denier Carlo Mattogno, and one of the world’s most active deniers, the convicted criminal Germar Rudolf.
Joe Mulhall, senior researcher at Hope not Hate, said: “These booksellers are providing a veneer of legitimacy to some of the world’s most extreme neo-Nazi and antisemitic tracts.
“These are works which have helped inspire extreme violence and terror plots, as well as driving hate towards minorities, particularly the Jewish community.
“It beggars belief that Amazon, Foyles, Waterstones and WHSmith would remain silent after the true nature of these works have been brought to their attention.
“It took too long for social media companies to react to hate and extremism on their platforms; surely the booksellers won’t make the same mistake in providing such easy access to racial hatred and vile antisemitic works now.”
Reacting to the investigation, Mr Arkush said: “The Board of Deputies has raised issues about such books with retailers like Amazon in the past, and we were dismayed to learn that these vile hate-filled books, are openly available on the websites of respected retailers.
“I would hope that these outlets are not seeking to profit from these heinous books, and therefore should urgently amend their policies and correct this appalling lapse."
Ruth Smeeth, Labour MP, also questioned why the major retailers continued to give the books the “veneer of respectability” by continuing to sell them on their websites.
Tom Tugendhat, Conservative MP, called on the booksellers to “think again” about the current policy.
