A cold case investigation led by an ex-FBI agent has identified a Jewish notary as the prime suspect in the mystery of who betrayed teenage diarist Anne Frank and her family to the Nazis, a new book claims.

Arnold van den Bergh may have revealed the Franks' hiding place in Amsterdam in order to save his own family, according to a six-year probe detailed in The Betrayal of Anne Frank by Canadian author Rosemary Sullivan, which is published on Tuesday.

The case against Van den Bergh, who died in 1950, is supported by evidence including an anonymous note sent to Anne's father Otto after World War II naming him as the betrayer, according to elements published in Dutch media Monday.

The Anne Frank House museum told AFP that the results of the probe, led by retired Federal Bureau of Investigation detective Vincent Pankoke, were a "fascinating hypothesis" but needed further investigation.

Theories have long swirled about the Nazi raid on August 4, 1944, that uncovered the secret annexe where Anne and her family hid from the Holocaust for two years.

Van den Bergh's name had previously received little attention but came to the fore during the investigation using modern techniques including artificial intelligence to sort through huge amounts of data. 

It narrowed the list of suspects to four, including Van den Bergh, who was a founding member of the Jewish Council, an administrative body the Nazis forced Jews to establish to organise deportations.

Investigators found he had managed to get his family exempted from being transported, but that this was revoked around the time of the betrayal of the Franks.

The cover of the book. Photo: Twitter.com

"We do not have a smoking gun, but we do have a hot weapon with empty casings next to it," Pankoke was quoted as saying by Dutch public broadcaster NOS.

After the raid on the Franks' house, the family were deported and Anne and her sister died in the Bergen-Belsen concentration camp the following year.

Her father later published her Diary of a Young Girl which has since sold more than 30 million copies.

Ronald Leopold, executive director of the Anne Frank House, said questions remained about the anonymous note in particular.

"You have to be very careful about sending someone down in history as a traitor to Anne Frank if you are not 100 or 200 per cent sure about that," he added.