Extensive research leads to a new suspect in Anne Frank's betrayal but some experts remain cautious on the conclusions because concrete evidence lacks to prove the theory.
A team of historians, criminologists, data specialists spent six years researching on the mystery of how Nazis found the hideout of Anne Frank, the famous young diarist who died in 1944.
And the conclusions of the research support a theory barely considered until now.
Anne Frank would have been betrayed by a prominent Jewish notary, Arnold van den Bergh. He would have given away Anne's address, among others, to save his own family.
Anne and seven other Jews were discovered by the Nazis on August 4, 1944, after they had hid for nearly two years in a secret annex above a canal-side warehouse in Amsterdam. All were deported. Anne died in a camp when she was 15.
"This was not a cold case. The case was frozen", said Vince Pankoke, former FBI agent who took part in the investigation.
An anonymous letter the central piece of the theory
The researchers used modern techniques like artificial intelligence to analyze 66 gigabytes of information. They compiled lists of Dutch collaborators, informants, historic documents, police records and visualized dozens of scenarios on maps trying to find connections between raids, hideouts or motives.
They initially tested 32 different theories, narrowing down to 4 names with Van Den Bergh as the lead suspect.
An anonymous letter sent to Anne's father is the central piece of their theory. The letter, discovered from a police investigation in the 1960s, said that Arnold van den Bergh gave out a list of hiding addresses to Nazis. It is the only document about the betrayal with a name mentioned.
Arnold van den Bergh was a member of the Jewish Council and the team speculates that, as a prominent local figure, he would have had access to hideout addresses. Furthermore, the raid ordered by a high-ranking Nazi could not have been tipped by an ordinary Dutch.
The Jewish Council was an Jewish organization created by the Nazis in 1941 to govern and liaise with the Jewish community in the Netherlands. The leadership was transferred to a concentration camp in 1943.
Arnold van den Bergh's theory have been dismissed in the past because he was allegedly deported a year before Anne Frank's arrest. But the investigators discovered that it wasn't the case.
Researchers even think Anne's father knew about the betrayal but wanted to avoid anti-Semitic conclusions. Van den Bergh was reinstated as a civil law notary after WWII and died of throat cancer in 1950.
No proof but speculation and confirmation bias?
Other experts praise the volume of documents obtained and analyzed but remain a lot more skeptical about the conclusions. Several pieces of the theory given by the investigators are challenged and could be explained differently.
The team itself recognized they didn't have a "smoking gun" to prove their theory. However, Pankoke estimates the probability to be correct is higher than 85%.
Ronald Leopold, the director of the Anne Frank House, which didn't participate but passed on documents to the investigation, thinks further research would be needed before throwing such an important conclusion, considering that "important puzzle pieces are still missing".
For Bart van der Boom, a university lecturer working on a book about the Jewish Council, the theory is a "defamatory nonsense", NOS reported.
For the University of Amsterdam's Holocaust and Genocide professor Johannes Houwink ten Cate, the Jewish Council was judged very harshly in the Jewish community: "If there had been any evidence that lists of Jews in hiding existed, it would have been brought forward after the war".
Historian Erik Somers of the Dutch NIOD institute for war, holocaust and genocide studies said the assumptions about the Jewish Council were not supported by other historical research. Many other reasons could also possibly explain why Van den Bergh, an influential figure, was never deported.
The motives and the timing of the letter are also questioned.
The findings of the new research were published in a book written by Canadian author Rosemary Sullivan, The Betrayal of Anne Frank on January 17 in the Netherlands and will be distributed in 23 countries.