A new study suggests that Anne and her family may have been found after police began investigating a ration fraud. The raid on Prinsengracht 263 in Amsterdam saw all those in hiding captured and sent to the death camps.
The Anne Frank House said: "The question has always been: Who betrayed Anne Frank and the others in hiding? This explicit focus on betrayal, however, limits the perspective on the arrest."
It was hitherto believed that before the raid on Anne's hiding place, an anonymous call was made to the Nazi security service Sicherheitsdienst (SD), but researchers are now questioning whether this is correct.
Looking at a diary entry from 10 March 1944, Anne writes about having "no coupons" due to the arrest of two men. The man are named as "B" and "D", which stood for Martin Brouwer and Pieter Daatzelaar. Both men worked as salesmen for a firm based in Prinsengracht 263, where Anne's father also had a business.
Anne writes into her diary on 14 March 1944: "B and D have been caught, so we have no coupons". This shows the Frank family were getting underhand coupons from these two men.
Looking at the police who discovered the family in their hideout, researchers also found they were not men usually tasked with searching for Jews in hiding, but usually worked on cases involving cash and security.
After more than two years in hiding, the Frank family was discovered in August 1944.
Anne Frank and her sister Margot died in February 1945 at the Bergen-Belsen concentration camp after surviving Auschwitz. Their mother, Edith, died a month earlier of starvation in Auschwitz. Her father Otto survived the Holocaust and later published Anne's diary, which became one of the world's best-known books.