Facebook has refused to remove pages where internet users espouse Holocaust denial despite a plea from a group of Holocaust survivors.

Earlier this month 21 survivors of Nazi persecution signed a letter which was sent to Facebook, asking that Holocaust denial no longer be allowed as part of facebook's "free speech" policy.

A Holocaust-denying British bishop who said "evidence was strongly against six million Jews having been deliberately gassed" has lost his appeal after being convicted of Holocaust denial.

It was supposed to be an ordinary day of work for Stephen Johns, a 39-year-old security guard at the US Holocaust Memorial Museum in Washington DC.

But in a tragedy that shocked the nation, Mr Johns, who was later described by colleagues as "a soft-spoken, gentle giant", was shot dead that afternoon by an octogenarian with ties to white supremacist groups.

A Guardian journalist has rounded on WikiLeaks as "disgraceful" and said Julian Assange and his colleagues should be ashamed of themselves for giving documents to "known antisemite and crook" Israel Shamir.

Holocaust denier David Irving has announced a speaking date in London, following a tour of the US.

His talk will take place at a secret location on May 21. The website reads: “You will be notified by email of the precise venue, a few days ahead of the date of the function.”

A recently published book by a former employee of WikiLeaks, Daniel Domscheit-Berg, argues that Julian Assange maintained close ties to a notorious antisemite.

Iranian audiences will have the chance to watch a film about the Holocaust next week thanks to an initiative by a French anti-racism group.

Education about the Nazi atrocities is minimal at best in a country whose president has publicly denied the Holocaust, but from Monday Claude Lanzmann’s 1985 documentary Shoah will be screened on an Iranian satellite channel.

In January 2009 it emerged that Pope Benedict had lifted the excommunication of a British bishop and known Holocaust denier.

The pope ordered Williamson to recant his views before the excommunication was lifted, but the issue provoked international outrage and threatened a rift in Jewish-Catholic relations.

The bishop, part of an extreme-traditionalist sect, had said: "I believe that the historical evidence is strongly against, is hugely against six million Jews having been deliberately gassed in gas chambers as a deliberate policy of Adolf Hitler".

"The Holocaust, on which independent research is strictly banned in the West, was nothing but a preposterous claim to settle European Jews in the Muslim land of Palestine by falsely creating a sense of oppression for the Zionists.

"Iran's President Mahmoud Ahmadinejad in statements applauded by all independent and conscientious people of the world has proposed due research on the supposed Holocaust."

Yad Vashem has begun broadcasting videos in Farsi.

The Israeli Holocaust memorial museum, which already has an Arabic YouTube channel, has launched the service in a bid to educate Iran’s population about the Nazis.

The videos will highlight the atrocities of the Second World War and the genocide of six million Jews to a population whose president, Mahmoud Ahmadinejad, has publicly questioned the Holocaust.

""The lie according to which they were a victim of a Holocaust and the [Jewish] people are a victim...this lie has crumbled with…the other countless Holocausts ... committed by the Zionist enemy."

The Greek government has described an antisemitic and Holocaust-denying slur by one of the country’s senior religious figures on national television as “unacceptable” and an insult to Greek culture.

Earlier this week the Metropolite of Piraeus Seraphim, a high-level priest, said in an interview on the country’s most influential television station that “Adolf Hitler was an instrument of world Zionism.”

An antisemitic writer who has been described by anti-Fascist campaigners as a Holocaust denier is believed to be working as a Russian distributor for WikiLeaks.

Israel Shamir, a Swedish resident who also uses the names Jöran Jermas and Adam Ermash, has been identified as the WikiLeaks staff member responsible for choosing which leaked documents are distributed in Russia.

It is also claimed that his journalist son Johannes Wahlström, known to share some of Mr Shamir’s views and previously criticised for faking reports, works for WikiLeaks in Scandinavia.