A fresh suspect has been identified in the upcoming ‘cold case’ documentary investigating who betrayed Anne Frank’s hiding place.

According to Variety and other news outlets (The New York Times, CNN) that investigators, including former FBI agents, believe Arnold van den Bergh, a one-time member of Amsterdam’s Jewish Council, may have been responsible for revealing Frank’s hiding place in the secret attic above her father’s office.  The documentary suggests that he did so in order to protect himself, although some evidence brought forth for this remains weak.

The undisputed evidence surrounding the event is that the Nazi SS discovered Frank, her parents, Otto and Edith, her elder sister Margot, a dentist named Fritz Pfeffer, and another family, the Van Pels, sheltering in the attic after getting a tip-off from an unknown source. All eight of the occupants were sent to Auschwitz.

Only Otto Frank survived of the eight Jewish occupants, with Anne passing at the age of 15 a mere weeks before Bergen-Belson, the camp to which she had been transferred, was liberated by British forces. Her sister had died only a few days before.

Upon returning the Amsterdam, Miep Gies, one of the caretakers of the Frank’s while they lived in the attic, had found Anne’s diary after they were forced to leave. She sought out Otto and returned the diary, and in turn, Otto decided to publish the diary. The Diary of Anne Frank was released in the United States and the United Kingdom in 1952, and it has since influenced numerous film and television adaptations.

In 2017, the Anne Frank Museum in Amsterdam, based in the building where the teenager and her family once hid, partnered with Proditione Media on Cold Case Diary, a re-investigation into who revealed the Frank’s hiding place to the Nazis.

The documentary, directed by Dutch filmmaker Thijs Bayens, investigative journalist Pieter van Twisk, and former FBI investigator Vince Pankoke, uses various modern techniques, including AI and forensic analysis and interviews with historians and other experts to re-examine the evidence.

A distributor nor a release date has been set for the documentary. The investigation has resulted in the book The Betrayal of Anne Frank by Rosemary Sullivan, which is getting published this week.