Karl Josef Silberbauer (21 June 1911 – 2 September 1972) was an Austrian police officer, Schutzstaffel (SS) member, and undercover investigator for the West German Bundesnachrichtendienst (federal intelligence service).
He was stationed in Nazi-occupied Amsterdam during World War II, where he was promoted to the rank of Hauptscharführer (master sergeant).
1935
Born in Vienna, Silberbauer served in the Austrian military before following his father into the police force in 1935.
1943
Four years later, he joined the Gestapo, moved to the Netherlands, and in 1943 transferred to the Sicherheitsdienst (SD) in The Hague.
He was then assigned to Amsterdam and attached to "Sektion IV B4", a unit recruited from Austrian and German police departments and which handled arrests of hidden Jews throughout the occupied Netherlands.
1944
On 4 August 1944, Silberbauer was ordered by his superior, SS-Obersturmführer (Lieutenant) Julius Dettmann, to investigate a tip-off that Jews were being hidden in the upstairs rooms at 263 Prinsengracht.
He took a few Dutch policemen with him and interrogated Victor Kugler about the entrance to the hiding place.
Miep Gies and Johannes Kleiman were also questioned, and while Kugler and Kleiman were arrested and the young secretary Bep Voskuijl managed to escape with documents that would have incriminated the black market of the Secret Annex protectors, Gies was allowed to stay on the premises.
She later surmised this was because she recognized and connected with Silberbauer's Viennese accent.
Both Otto Frank and Karl Silberbauer were interviewed after the war about the circumstances of the raid, with both describing Silberbauer's surprise that those in hiding had been there for more than two years.
Frank recalled Silberbauer confiscating their valuables and money, taking these spoils away in Otto Frank's briefcase, which he had emptied onto the floor, scattering out the papers and notebooks which made up the diary of Anne Frank.
Soon after, Kugler and Johannes Kleiman, together with Otto Frank, Edith Frank-Holländer, Margot Frank, Anne Frank, Hermann van Pels, Auguste van Pels, Peter van Pels, and Fritz Pfeffer, were arrested and taken to Gestapo headquarters in Amsterdam.
From there, the eight who had been in hiding were sent to the Westerbork transit camp and then to the Auschwitz concentration camp.
Soon after, Margot and Anne Frank were sent to the Bergen-Belsen concentration camp, where they died from typhus.
Victor Kugler and Jo Kleiman were sent to work camps.
Of the ten, only Otto Frank, Kugler, and Kleiman survived.
1945
Silberbauer returned to Vienna in April 1945 and served a fourteen-month prison sentence for using excessive force against members of the Communist Party of Austria.
After his release, Silberbauer was recruited by the West German Federal Intelligence Service (BND), and spent ten years as a mole, or undercover operative.
According to Der Spiegel reporter Peter-Ferdinand Koch, who learned of his postwar activities while researching BND employment of former Nazis, Silberbauer infiltrated neo-Nazi and pro-Soviet organizations in West Germany and Austria.
His BND handlers believed, correctly, that Silberbauer's past membership in the SS would blind neo-Nazis to his true loyalties.
1948
During the 1948 Dutch police investigation into the raid on the Secret Annex, Silberbauer's name had been disclosed as "Silvernagel".
The Dutch police detectives who had assisted with the raid were identified by Miep Gies, who recalled their commander as having a working-class Vienna accent.
The Dutch policemen claimed to remember nothing except an erroneous form of their superior's surname.
Wiesenthal considered contacting Anne's father, Otto Frank but learned that he was speaking out in favor of forgiveness and reconciliation.
Otto also believed that the person responsible for the denunciation of the Gestapo, not the arresting officers, bore the greatest responsibility.
Wiesenthal, however, was determined to discredit the growing Holocaust denial movement and continued his search for "Silvernagel".
1954
Possibly due to BND pressure, Silberbauer was reinstated by the Viennese Kriminalpolizei (Kripo) in 1954, four years after the German publication of Anne Frank's diary, and promoted to the rank of Inspektor.
1958
Holocaust survivor and Nazi hunter Simon Wiesenthal began searching for Silberbauer in 1958, upon being challenged by Austrian Holocaust deniers to prove that Anne Frank existed.
One teenaged Holocaust denier stated that, if Anne Frank's arresting officer were found and admitted to it, he would change his mind.
1963
In 1963, Silberbauer, by then an inspector in the Vienna police, was exposed as the commander of the 1944 Gestapo raid on the Anne Frank House Secret Annex and the arrests of Anne Frank, her fellow fugitives, and two of their protectors, Victor Kugler and Johannes Kleiman.
In late spring 1963, after ruling out numerous Austrians with similar names, Wiesenthal was loaned a wartime Gestapo telephone book by Dutch investigators.
During a two-hour flight from Amsterdam to Vienna, Wiesenthal found the name "Silberbauer" listed as attached to "Sektion IV B 4".
Upon his arrival in Vienna, Wiesenthal immediately telephoned Dr.Josef Wiesinger, who investigated Nazi crimes for the Austrian Ministry of the Interior.
Upon being told that Silberbauer might still be a policeman, Wiesinger insisted that there were "at least six men on the Vienna police force" with the same surname and demanded a written request.
On 2 June 1963, Wiesenthal submitted a detailed request but was told for months that the Vienna police were not yet ready to release their findings.
In reality, the Vienna police identified Inspektor Silberbauer almost immediately.
When he had admitted his role in arresting Anne Frank, the department had been terrified of the bad press that would result from disclosing his past.
Therefore, the Vienna police suspended Silberbauer from the Kripo without pay, ordering him to "keep his mouth shut" about the reasons for his suspension.
Instead, Silberbauer lamented his suspension and disclosed the reasons for it to a colleague.
His fellow officer, a member of the Communist Party of Austria, immediately leaked the story to the party's official newspaper, who published it on 11 November 1963.
