German media reported that prosecutors said Wednesday that the clemency plea filed by Oskar Groening was rejected, Reuters reported.

“The clemency request has been denied,” Wiebke Bethke, a spokeswoman for the prosecutors’ office in Lüneburg told news agency epd.

Groening could still appeal his clemency request to the Justice Ministry of Lower Saxony, the northern German state where his 2015 trial took place, German public broadcaster Deutsche Welle reported.

He is expected to go to prison by the end of the month.

Groening, known as the “bookkeeper of Auschwitz,” was convicted and sentenced in July 2015 to four years in jail for his role in the murder of 300,000 Hungarian Jews at the concentration camp in Nazi-occupied Poland. A federal appeals court rejected his appeal a year ago. He had remained free while waiting for a determination of his fitness to serve time in prison after requesting that the sentence be suspended.

Germany’s constitutional court, the country’s highest court, last month rejected Groening’s appeal, ruling that he could receive appropriate health care in prison, and that his jail sentence could be “interrupted” should there be a change in the nonagenarian’s health.

Groening had admitted to being tasked with gathering the money and valuables found in the baggage of murdered Jews and handing it over to his superiors for transfer to Berlin. He said he had guarded luggage on the Auschwitz arrival and selection ramp two or three times in the summer of 1944.

During the trial, Groening asked for forgiveness while acknowledging that only the courts could decide when it came to criminal guilt.