However, he admitted sharing a platform with the Ku Klux Klan, which has carried out racist attacks across America’s Deep South, and defended leaders in the organisation as "non-violent".
The BNP leader could not explain why he had previously sought to play down the Holocaust and defended his use of Sir Winston Churchill on BNP literature on the basis that his father had fought in the Second World War.
He claimed that Churchill would have been a member of the BNP and was "Islamophobic" by "today’s standard".
Asked whether he denied that millions of Jews and other minorities had been killed by the Nazis, Mr Griffin would only reply: "I do not have a conviction for Holocaust denial."
He was then chastised by David Dimbleby, the host of the programme, for smiling.
The controversial statements were made in response to intense questioning by members of the audience from ethnic minorities.
BBC Television Centre in west London came under siege as filming took place, with MPs joining hundreds of protesters behind lines of police. There were six arrests as dozens of protesters attempted to storm the studio.
BBC studios in Hull, Scotland and Wales were also targeted by demonstrators. The cost of the police operation was estimated to be more than £100,000.
The BBC was certain to be questioned over why it allowed Mr Griffin to air such controversial views but executives were hoping that the intensive questioning that he faced would justify their decision to invite him on the Question Time panel for the first time.
The BBC, which Mr Griffin denounced on the programme as "ultra-Leftist", had claimed that impartiality rules meant that it had little choice but to invite him on to the programme after the BNP won seats in the European Parliament in elections earlier this year.