The remains of 300 people killed by the Nazis and used by a German doctor for research will be buried in Berlin in May 2019.

The late Hermann Stieve kept tissue samples of the mostly female victims after he dissected their bodies for his research at the University of Berlin.

He sometimes received the bodies of resistance fighters minutes after they were killed at the Berlin-Ploetzensee prison, the German newspaper Bild am Sonntag reported. The samples were found in small black boxes and some were labelled with the name of the victim.

Stieve was researching menstruation and the effects of stress on the reproductive system. He died of a stroke in 1952.

The samples were discovered by his heirs and turned over to Berlin’s Charité university hospital. They will be buried on May 13.

Although Stieve’s research is widely considered to have violated medical ethics, he was elected to the German Academy of Sciences at Berlin and the German Academy of Sciences Leopoldina.

The Royal Swedish Academy of Sciences also extended membership to him in recognition of his research.