According to new research, a Jewish notary from Amsterdam betrayed the Frank family in the Second World War, leaking the address of Anne Frank’s hiding spot to the Nazis.

International team investigates what happened to the Frank family

A team of 23 international investigators have looked into what happened to Anne Frank and her family when they were discovered and arrested by the Nazis in 1944, using modern technology and new techniques to determine how the address of the Achterhuis ("the secret annexe") came to be known. 

After years of work, the researchers have concluded that a prominent Amsterdam-based Jewish notary, Arnold van den Bergh, passed on the addresses of Jewish hiding spots to the Nazis in order to protect himself and his family. 

Otto Frank's anonymous note holds the key

The credibility of this theory rests on one key piece of evidence: an anonymous note that was delivered to Otto Frank shortly after the war which read “Your hiding place in Amsterdam was reported…by A. van den Bergh, who at the time lived near Vondelpark, O. Nassaulaan. At the JA there was a whole list of addresses passed on by him."

When Otto Frank shared the note with Dutch police in the 1960s, the allegations were ignored as officered argued Van den Bergh had been arrested in 1943 and so it was unlikely he was leaking information to the Nazis from inside a concentration camp. 

However, information has since revealed that he was never arrested, and when it looked as though he was facing deportation in 1944, he likely traded information the Jewish Council had compiled on hiding places for the ensured safety of him and his family. As a prominent member of the Jewish Council, it’s possible he could easily access these documents.

Uncovering the mystery of Anne Frank’s discovery

While there is no hard evidence to confirm this theory, retired FBI detective Vince Pankoke is convinced this is what happened to those hiding in the Achterhuis: “Because there is no DNA evidence or video images in such an old case, you will always have to rely on circumstantial evidence. Yet our theory has a probability percentage of at least 85 percent; we do not have a smoking gun, but we do have a hot weapon with empty casings next to it."

The team used modern police methods and investigative techniques to solve one of the biggest mysteries from the Second World War, collecting interviews, diaries, address lists and war files in order to determine exactly what happened almost 80 years ago. 

They used artificial intelligence to dig through 66 gigabytes of information, putting various new and old hypotheses to the test. Their methods and findings were published in The betrayal of Anne Frank on Monday. "All in all, we have inventoried about thirty theories," explains Dutch journalist and researcher Pieter van Twisk. “We can say that 27, 28 of them are very unlikely or impossible."