Former nurse Niels Hoegel, accused of killing more than 100 patients in his care, will go on trial Tuesday in the biggest serial killing trial in Germany’s post-war history.

Hoegel, 41, has already spent nearly a decade in prison for other patient deaths, and is accused of intentionally administering medical overdoses to victims so he could bring them back to life at the last moment.

He is to face questioning before dozens of victims’ anguished loved ones who still hope to learn the full scope of his murder spree.

The trial in Oldenburg, northern Germany, is set to last until at least May, with the first hearing to focus on prosecutors presenting their case.

Hoegel, who is already serving a life term, has confessed to dozens of killings.

Investigators say at least 36 patients were killed at a hospital in Oldenburg where he worked, and about 64 more at a clinic in nearby Delmenhorst, between 2000 and 2005.

“I hope he will be found guilty on each count so that the loved ones can finally find some closure,” said Petra Klein, who runs the local chapter of the victims’ aid group Weisser Ring.

Around 126 relatives will be co-plaintiffs in the new trial and are expected to fill the specially designated courtroom in Oldenburg, along with about 80 journalists.

More than 130 bodies of patients who died on Hoegel’s watch have been exhumed, in a case investigators have called “unprecedented in Germany to our knowledge”. (AFP)

•German former male nurse Niels Hoegel (L) hides his face behind a folder as he waits for the opening of another session of his trial at a court in Oldenburg, northwestern Germany.