A decision to investigate 30 alleged former guards at Auschwitz was prompted by the case of Ukraine-born John Demjanjuk.
Demjanjuk was the first Nazi war criminal to be convicted in Germany without evidence of a specific crime or victim but purely on the grounds he had served as death camp guard.
He died last year, aged 91, while appealing against a five-year jail sentence for complicity in the murder of more than 28,000 Jews at the Sobibor camp in Poland.
German justice officials have called for 30 alleged former Nazi guards to face prosecution for their role in facilitating mass murder at the Auschwitz death camp during World War Two.
– Chief prosecutor Kurt Schirm
"The accused ... are all former guards at the concentration camps Auschwitz-Birkenau and we take the view that this job - regardless of what they can be individually accused of - makes them guilty of complicity in murder
The Special German prosecutors' office that investigates Nazi war crimes is recommending pursuing charges against 30 alleged former Auschwitz guards, according to justice officials.
Prosecutors investigated 50 former guards and decided pursue 30 cases, the Baden-Wuerttemberg Justice Ministry said.
Renewed investigations of death camp guards come after the case of John Demjanjuk, who died last year while appealing his 2011 conviction on allegations he served in Sobibor.
His case established that death camp guards could be convicted as accessories to murder, even where there was no specific evidence of atrocities against them.