The main railway building at Auschwitz-Birkenau (Reuters)

Six elderly women are being investigated over their role as prison guards at the infamous Nazi death camp, Auschwitz.

Germany's Central office for the investigation of National Socialist crimes have to demonstrate that the women, now at least 87 years old, worked also at the Birkenau death site. Birkenau was used as a mass murder site alongside the forced labour camp at the Auschwitz complex in Poland. More than 1.3 million people were gassed and murdered at the site, 90pc of them Jews.

The John Demjanjuk case, who served as a guard at Sorbibor and Majdanek, showed that having been a guard at a concentration camp could give enough ground for prosecution.

Lists from two Nazi death camps, Auschwitz and Majdanek, survived after the Second World War, providing information on 80 names of living Nazi war crime suspects.

An investigator from the Central Office in Ludwigsburg, near Stuggart, which researches the archives of these lists, told The Times that there are conducting investigations on the grounds of aiding and abetting murder for those who were working as guards at the camps, also for women.

Its archives contain 1.7 million index cards with information on 700,153 names, 628,093 places and 373,412 military units or actions

The head of the Central office said that there are no information on executions conducted by female guards, but some of them treated prisoners very brutally and have been convicted of war crimes. The Central office released only the name of a male suspect, Hans Lipschis, aged 93, who was arrested in May for complicity in mass murder at Auschwitz. He said he was a cook.

Hunt for Hitler's Former Auschwitz Female Guards - Youngest is 87
Female Nazi prison guards sentenced to death in 1946 for for murder and acts of brutality against their prisoners.