Ursula Haverbeck, dubbed the “Nazi-Oma” (Nazi grandma) by German media, was convicted in October on eight counts of incitement and sentenced to two years behind bars.
But she did not report to prison to start her sentence by an April 23rd deadline.
“After the convict failed to report to the relevant penal institution within the deadline, prosecutors in Verden on May 4th, 2018 issued an order to execute the sentence and have charged police with its implementation,” prosecutors said in a statement.
The woman was later on Monday located at her home in the northwestern town of Vlotho, DPA news agency reported, citing local police and prosecutors.
She was arrested and immediately transferred to prison.
Haverbeck was once chairwoman of a far-right training centre shut down in 2008 for spreading Nazi propaganda.
She has been sentenced on several occasions to jail for Holocaust denial.
During a trial in 2015, she insisted that Auschwitz was “not historically proven” to be a death camp.
That is “only a belief,” said Haverbeck then. She has also gone on television to declare that “the Holocaust is the biggest and most sustained lie in history”.
Some 1.1 million people, most of them European Jews, perished between 1940 and 1945 in the Auschwitz-Birkenau camp before it was liberated by Soviet forces.