(AFP) BERLIN — Germany’s jailed “Nazi grandma” Ursula Haverbeck, 89, on Friday lost a challenge before the country’s highest court, which reaffirmed that constitutional free speech guarantees do not cover Holocaust denial.

Haverbeck started her latest prison term in May for insisting that Nazi Germany’s mass murder of millions of Jews and others was “only a belief” and that Auschwitz was “not historically proven” to have been a death camp.

German law makes it illegal to deny the genocide committed by Adolf Hitler’s regime, which in the Auschwitz-Birkenau camp in occupied Poland alone claimed some 1.1 million lives, mostly of European Jews.

Holocaust denial and other forms of incitement to hatred against segments of the population carry up to five years in prison, while the use of Nazi symbols such as swastikas is also banned.

The Constitutional Court ruled that “punishment for denying the National Socialist genocide is fundamentally compatible with Article 5 (1) of the Basic Law,” which guarantees freedom of speech.

“The dissemination of claims that are proven to be untrue and of deliberately false assertions” was not covered by free speech, the court ruled, adding that Holocaust denial “breaches the limits of peaceful public debate and represents a disruption of the public peace.”

Haverbeck, who was once chairwoman of a far-right training centre shut down in 2008 for spreading Nazi propaganda, was convicted in October last year on eight counts of incitement and sentenced to two years behind bars.

She had previously been sentenced on several occasions to jail for denying the Nazi genocide, once declaring on television that “the Holocaust is the biggest and most sustained lie in history.”