Ursula Haverbeck-Wetzel
Holocaust denier Ursula Haverbeck, 88, arrives for her trial at the Amtsgericht Tiergarten courthouse in Berlin on 16 October 2017 Steffi Loos/Getty Images

An 88-year-old woman known as the 'Nazi grandma' was sentenced to six months in jail for saying there were no gas chambers at the Auschwitz concentration camp - the fifth conviction for the repeat Holocaust denier.

Ursula Haverbeck was sentenced at a Berlin district court on Monday (16 October) for saying at an event last January in the German capital that the Holocaust did not take place and that there were no mass deaths at the infamous Auschwitz camp.

Ursula Haverbeck has often denied the mass murder of millions of Jews by the Nazis, which constitutes incitement of racial hatred under German law. She filed an immediate appeal against Monday's ruling.

Haverbeck has been convicted on several occasions, but she has not served any jail time, as all her cases are still under appeal.

She has previously been charged with Holocaust denial, for the content of several articles she wrote for a magazine called the Voice of the Reich.

At the January meeting Haverbeck repeated her claims, saying it was "not true" that there were gas chambers at the Auschwitz concentration camp. She disputed the fact that 1.1 million people were killed at the camp in Nazi-occupied Poland.

Haverbeck is a notorious extremist who was once chairwoman of a far-right training centre shut down in 2008 for spreading Nazi propaganda. She is also a friend of Gudrun Burwitz, the elderly daughter of Nazi SS chief Heinrich Himmler.

The pensioner has also appeared on television and said that "the Holocaust is the biggest and most sustainable lie in history".

A court spokeswoman said that Haverbeck would only be imprisoned if an appeal fails and if she is declared fit by doctors to serve time in jail.

Haverbeck was most recently convicted of Holocaust denial in September 2016, when she was sentenced to eight months in prison. But that decision, like all her other convictions, is under appeal.

Haverbeck wrote a letter in February to the mayor of Detmold when a former Auschwitz guard was going on trial there, claiming the notorious Nazi death camp was only a labour camp and called survivors "alleged witnesses."

In Germany, anyone who publicly denies, endorses or underplays the extermination of Jews during Adolf Hitler's regime can be sentenced to a maximum of five years in jail.

The overwhelming majority of historians agree that around six million people, including Jews, gays, Gypsies, the disabled and other persecuted minorities, were killed during the Holocaust during the Second World War.