A court in the eastern German town of Neubrandenburg brought proceedings to a halt on Monday, after 95-year-old Hubert Z., received a doctor's note saying he was unfit to attend the hearing.

An appeals court in Rostock in northern Germany said in December that Hubert Z. was fit for trial - overruling a previous decision by a lower court that considered him too fragile for a legal process. Just two weeks ago, however, the trial was suspensed again due to the defendant's "failing health." Defense attorney Peter-Michael Diestel claims his client has a form of dementia.

Hubert Z. worked as a medic at Auschwitz concentration camp in Nazi-occupied Poland from August 15, 1944 to September 14, 1944. During that time, 14 trains carrying prisoners arrived at Auschwitz-Birkenau, where many would eventually be murdered in the gas chambers.

'Insidious and cruel killings'

Prosecutors say the Hubert Z.'s unit was involved in putting Zyklon-B pesticide crytals into Auschwitz's gas chambers, where up to 6,000 Jews were killed per day, and was "supportive of the running of this extermination camp."

"The accused lent support to the organization of the camp and was thereby both involved in and advanced the extermination with these insidious and cruel killings of at least 3,681 people," the prosecutors charge.

A Polish court jailed Hubert Z. in 1948 for his role at Auschwitz. He returned home to Neubrandenburg, after serving his three-year sentence.

Hunt for Nazi perpetrators

German prosecutors have come under pressure in recent years to bring the last surviving Holocaust criminals to justice. The new head of the Central Office for the Investigation of National Socialist Crimes, Jens Rommel, said in February that German authorities would continue looking for Nazi war criminals for the foreseeable future, despite the 70 years that have elapsed since the end of the Second World War.

Editor's note: Deutsche Welle follows the German press code, which stresses the importance of protecting the privacy of suspected criminals or victims and obliges us to refrain from revealing full names in such cases.