A German court said on Wednesday that this week’s session in the trial of a 93-year-old former SS sergeant who served in the Auschwitz death camp has been called off due to the defendant’s poor health, The Associated Press (AP) reported.

The Lueneburg state court said that Oskar Groening, nicknamed “the Bookkeeper of Auschwitz”, was ill and not able to stand trial on Thursday as planned.

Groening is charged with 300,000 counts of accessory to murder on allegations he helped the death camp function in his job sorting cash and valuables seized from Jews.

He told the court as the trial opened last month he felt a “moral guilt” but said it was up to the judges to decide if he was legally guilty.

The trial is to resume next Tuesday, according to AP. One other session has already been canceled due to Groening’s health.

In recent years, Germany has begun a crackdown on Nazi war criminals. The crackdown began following the 2011 Munich trial of John Demjanjuk, a Nazi war criminal charged of assisting in the murder of 28,060 people at the Sobibor death camp and sentenced to five years. The former Nazi died in 2012.

A 93-year-old man, who was not identified, was recently charged in a German court with 170,000 counts of accessory to murder on allegations he served as an SS guard at the Auschwitz death camp.