A Berlin historian has uncovered how a Berlin pastor spent a decade searching the registry of the Lutheran church in Berlin for "non-Aryan Christians" and passed over 2,600 names onto the Nazis.
In November 1934, the Rev Karl Themel, then a 44-year old pastor of a Berlin city centre parish, wrote to the notorious Institute for Racial Research offering to help them in their work.
Mr Manfred Gailus, a historian at Berlin's Technical University who has researched the story, says the Nazis were very interested in the offer from Mr Themel, a trained genealogist and a self-described "Christian National Socialist".
Mr Themel was in a position to give the Nazis information on hundreds of Jews who had "disappeared" from the Jewish community in Berlin by marrying non-Jews.
He published a pamphlet in 1936, with Nazi funding, describing how to establish "where and when Jewish blood had forced its way into the body of the German people".
From that year on, over 50 clerks employed by the Lutheran church at the harmless-sounding "Old Berlin Church Registry" made copies of Berlin parish registries, while at the same time sending information about people of "Jewish creed" or those who once held a "Jewish name" to Nazi officials.
"Although we have no official agreement with the Ministry for Racial Research on handing over racially-relevant findings, work practices have made it necessary to enter an exchange relationship with several government departments," Mr Themel wrote in 1938.
At the fifth anniversary party of the "Old Berlin Church Registry", Mr Themel congratulated his staff on their work, cataloguing all Jews listed in the Berlin Lutheran church registry since 1874.
"In total some 2,612 cases of Jewish origin were confirmed," he told the workers in December 1941, just weeks after the deportation of Jews began.
Rev Karl Themel's role as a kind of anti-Oskar Schindler was never fully investigated by the Lutheran Church and he continued to work as a pastor until his death in 1973 aged 83.
After his death, the church praised Mr Themel for his "tireless work and passionate interest in cataloguing the genealogy of Berlin".