Mark Zuckerberg has been condemned for saying Holocaust deniers were not "intentionally getting it wrong".

Facebook has faced difficult questions about how it deals with hate speech on the social media and Mr Zuckerberg, its founder and chief executive, cited Holocaust denial as something the site might leave up. 

During an interview on tech podcast ReCode, Mr Zuckerberg said: "At the end of the day, I don't believe that our platform should take that down because I think there are things that different people get wrong... I don't think that they're intentionally getting it wrong."

He also said: "It's hard to impugn intent and to understand the intent. I just think, as abhorrent as some of those examples are, I think the reality is also that I get things wrong when I speak publicly."

The comments triggered huge anger. 

Jonathan Greenblatt, chief executive of the Anti-Defamation League, a Jewish NGO that fights antisemitism, said: “Holocaust denial is a willful, deliberate and longstanding deception tactic by anti-Semites that is incontrovertibly hateful, hurtful, and threatening to Jews.

"Facebook has a moral and ethical obligation not to allow its dissemination. ADL will continue to challenge Facebook on this position and call on them to regard Holocaust denial as a violation of their community guidelines.”

Karen Pollock, Chief Executive of the Holocaust Educational Trust, added: “Denying and distorting the truth of the Holocaust is antisemitism and constitutes hate speech.

“Free speech is a fundamental value of our society, but when it comes to Facebook pages entitled 'Anti Holocaust' or 'Holohoax' that actively churn out antisemitic propaganda, you have to ask whether values of tolerance and positive race relations are being upheld.

“Images of a burning Star of David captioned, 'Now we’re burning your flag, don’t force us to burn you' or calling the Holocaust 'the greatest scheme' are deliberate and inciteful. Mr Zuckerberg should take the lead and stamp out Holocaust denial and antisemitism from his platform.”

Mr Zuckerberg later emailed Kara Swisher, the podcast host who interviewed him, to walk back his comments.

He wrote: "I personally find Holocaust denial deeply offensive, and I absolutely didn't intend to defend the intent of people who deny that."