Ursula Haverbeck-Wetzel, 87, has been sentenced by a district court in Bad Oeynhausen, North Rhine-Westphalia, to 11 months imprisonment without parole, Süddeutsche Zeitung reported on Tuesday.
Haverbeck-Wetzel was convicted for the crime of incitement of hatred for denying the Holocaust in a letter she sent to the Central Council of Jews in Germany, as well as on her website.
In Germany, the crime of incitement of hatred refers to actions that encourage hatred or violence towards a group of people because of their religion, race or ethnic background. It also punishes any individual, who publicly "approves of, denies or downplays" the actions of the Nazis which violated international law, by up to five years in prison.
More than 1 million people were killed at Auschwitz through gas chambers, starvation or medical experiments, and most were European Jews.
Haverbeck-Wetzel was sentenced to ten months in prison last November for incitement of hatred after she went on television to declare that "the Holocaust is the biggest and most sustainable lie in history".
A court in Detmold, North-Rhine Westphalia, also recently sentenced her to eight months in prison for her Holocaust denial - which she has appealed - and a further case is ongoing in Verden, outside Bremen.
Haverbeck-Wetzel is well known among far-right groups, having been a member of two groups banned in 2010 for their extremist views: the "Collegiums Humanum", of which she was chair, and an association she helped found to help people who were "persecuted" for denying the Holocaust.