Prime Minister Stephen Harper joined a growing chorus of world leaders in condemning a conference in Iran that questions the Nazi genocide of Jews.

"On behalf of the government of Canada, I want to condemn, in the strongest terms, this latest example of anti-Israeli and racist statements from the president of Iran," Harper said in a statement.

"In addition, the conference hosted by President Mahmoud Ahmadinejad with the sole purpose of denying the Holocaust is an offence to all Canadians."

Earlier, British Prime Minister Tony Blair denounced the two-day conference, which ends Tuesday, as "shocking beyond belief" and "a symbol of sectarianism and hatred toward people of another religion." He told reporters in London that the conference, the brainchild of Ahmadinejad, only proved the Iranian leader's extremism.

"I mean, to go and invite the former head of the Ku Klux Klan to a conference in Tehran which disputes the millions of people who died in the Holocaust … what further evidence do you need that this regime is extreme?" he said.

The gathering of Holocaust deniers in Iran touched off a firestorm of indignation across Europe, where some countries have outlawed public denial that six million Jews were slaughtered during the Second World War. Israel's prime minister, German leaders and the European Union's top justice official are among those who have denounced the conference.

'We have learned and memorized the lesson [of the Holocaust]; the weak and defenceless are doomed. Doomed are they who do not believe those who threaten to eradicate them.'—Israeli PM Ehud Olmert

The conference began Monday in Tehran and brought 67 participants from 30 countries, including the former Imperial Wizard of the Ku Klux Klan David Duke, a well-known French academic who lost tenure over his anti-Holocaust opinions, several Orthodox Jews and other prominent Holocaust skeptics.

Israeli Prime Minister Ehud Olmert called the event "a sick phenomenon" Tuesday as he met with German leaders in Berlin, urging them to sever economic ties with Iran.

During a visit to Berlin's Grunewald train station, where thousands of Jews were transported to death camps during the Holocaust, Olmert referred to Iran's attempts to deny the events of the Holocaust.

"We have learned and memorized the lesson [of the Holocaust]; the weak and defenceless are doomed. Doomed are they who do not believe those who threaten to eradicate them. Doomed are the complacent. Doomed are they who entertain the false illusion that they could escape harm and that they could rely on the mercy of strangers," Olmert said.

The German parliament's president, Norbert Lammert, protested the conference in a letter to Ahmadinejad and dismissed it as anti-Semitic propaganda.

EU justice chief joins condemnation

Ahmadinejad, who has referred to the well-documented Nazi genocide as a "myth" and called for Israel to be "wiped off the map," initiated the two-day conference.

Since the end of the Second World War, Germany has paid billions of dollars in reparations to Israel and relations between the two countries remain strong, with Israel's security being a pillar of German foreign policy.

The European Union's top justice official, Franco Frattini, also joined the chorus of condemnation.

The conference shows an 'utter disregard of historically established facts.'—Franco Frattini,the EU's top justice official

Frattini issued a statement Tuesday that said the Iran conference shows an "utter disregard of historically established facts."

The conference was "an unacceptable affront not only to the victims of that tragedy and their descendants, but also to the whole democratic world," he said.

Conference defended as free-speech issue

Organizers have defended the conference as a free-speech issue. They said they wanted to create an environment where scholars can freely debate the Holocaust away from Western taboos or persecution.

It is illegal to deny aspects of the Holocaust in some countries, including France, Germany and Austria, and some of the speakers at the conference have been charged and even jailed for denying aspects of the Holocaust.

The conference organizers, like many of the attendees, also argue that the Holocaust is used to justify the existence of a Jewish state and Israeli oppression of Palestinians.

'The Zionists have used the Holocaust as a weapon to deny the rights of the Palestinians and cover up the crimes of Israel.'—Former KKK leader David Duke

The organizers said the conference was not an explicit attempt to deny the Holocaust happened, but merely to call into question its scale and methods.

"The Zionists have used the Holocaust as a weapon to deny the rights of the Palestinians and cover up the crimes of Israel," Duke, the former KKK leader, said in an address Monday.

Duke, who once ran to be U.S. president and a member of Congress, also said the gas chambers in which millions perished did not actually exist.

The speakers included Robert Faurisson, who was a literature professor at a French university until being stripped of his tenure for repeated public denials that the Holocaust took place.

He was the subject of great controversy in France, especially after renowned American scholar Noam Chomsky defended his right to free speech.

In Faurisson's speech at the conference, he said the Holocaust was "no more than a belief" created to justify the creation of Israel.

Members of a group of radical rabbis, Jews United Against Israel, also attended the conference. They don't doubt the existence of the Holocaust, but object to the state of Israel on religious grounds.

With files from the Associated Press