A German federal court has thrown out a 95-year-old former Auschwitz death camp guard’s appeal against his conviction for being an accessory to murder.

The decision to uphold Oskar Gröning’s conviction sets an important precedent for German prosecutors’ efforts to pursue others who allegedly served at Nazi death camps.

Gröning was convicted in July 2015 of being an accessory to the murder of 300,000 Jews and sentenced by a court in Lüneburg to four years in prison.

Gröning testified at his trial that he oversaw the collection of prisoners’ belongings and ensured valuables and cash were separated to be sent to Berlin. He said he witnessed individual atrocities, but did not acknowledge participating in any crimes.

On Monday, the federal court of justice said it had thrown out Gröning’s appeal. It also rejected appeals from several survivors and their relatives who had joined the trial as co-plaintiffs, as is allowed under German law, and had sought more serious charges.

It is the first time an appeals court has ruled on a conviction obtained under the logic that serving at a death camp, and thus helping it operate, was enough to convict someone as an accessory to the murders committed there – even if there was no evidence of involvement in a specific killing.

At the original trial, the presiding judge, Franz Kompisch, said Gröning was part of the “machinery of death,” helping the camp function and also collecting money stolen from the victims to help the Nazi cause.

The federal court noted that Gröning’s responsibilities had included keeping watch on the inmates and preventing resistance or attempts to flee by force.

In 2011, John Demjanjuk, a former Ohio autoworker, became the first person convicted in Germany solely for serving as a death camp guard without evidence of being involved in a specific killing. Demjanjuk, who always denied serving at the Sobibor camp, died before his appeal could be heard.