BERLIN — A German court rejected a former Auschwitz death camp guard’s appeal of his conviction for being an accessory to murder, a decision viewed as setting an important precedent for future prosecutions of Holocaust perpetrators.

Oskar Groening, now 95, was convicted in July 2015 of being an accessory to the murder of 300,000 Jews and sentenced to four years in prison. Judges found that he knew Jews were being slaughtered and supported the killings through his actions.

The Federal Court of Justice’s decision to uphold the former SS sergeant’s conviction boosts cases against other suspects and raises the possibility of more investigations of others who served at Nazi death camps. ‘‘It’s very exciting news,’’ said Efraim Zuroff, head Nazi hunter at the Simon Wiesenthal Center in Jerusalem.

Groening, dubbed the ‘‘accountant of Auschwitz,’’ testified he oversaw the collection of prisoners’ belongings and ensured valuables were separated to be sent to Berlin.

He said he witnessed individual atrocities but did not acknowledge participating in any crimes.

Presiding Judge Franz Kompisch ruled last year, however, that Groening was part of the ‘‘machinery of death.’’

In throwing out Groening’s appeal, the federal court noted that his responsibilities had included keeping watch on the inmates and preventing resistance or attempts to flee, by force if necessary.