As reported in The New York Times in 2015, "When Otto Frank first published his daughter's red-checked diary and notebooks, he wrote a prologue assuring readers that the book mostly contained her words".[75] Although many Holocaust deniers, such as Robert Faurisson, have claimed that Anne Frank's diary was fabricated,[76][77] critical and forensic studies of the text and the original manuscript have supported its authenticity.[78]
The Netherlands Institute for War Documentation commissioned a forensic study of the manuscripts after the death of Otto Frank in 1980. The material composition of the original notebooks and ink, and the handwriting found within them and the loose version were extensively examined. In 1986, the results were published: the handwriting attributed to Anne Frank was positively matched with contemporary samples of Anne Frank's handwriting, and the paper, ink, and glue found in the diaries and loose papers were consistent with materials available in Amsterdam during the period in which the diary was written.[78]
The survey of her manuscripts compared an unabridged transcription of Anne Frank's original notebooks with the entries she expanded and clarified on loose paper in a rewritten form and the final edit as it was prepared for the English translation. The investigation revealed that all of the entries in the published version were accurate transcriptions of manuscript entries in Anne Frank's handwriting, and that they represented approximately a third of the material collected for the initial publication. The magnitude of edits to the text is comparable to other historical diaries such as those of Katherine Mansfield, Anaïs Nin and Leo Tolstoy in that the authors revised their diaries after the initial draft, and the material was posthumously edited into a publishable manuscript by their respective executors, only to be superseded in later decades by unexpurgated editions prepared by scholars.[79]
Nazi sympathizer Ernst Römer accused Otto Frank of editing and fabricating parts of Anne's diary in 1980. Otto filed a lawsuit against him, and the court ruled that the diary was authentic. Römer ordered a second investigation, involving Hamburg's Federal Criminal Police Office (Bundeskriminalamt (BKA)). That investigation concluded that parts of the diary were written with ballpoint pen ink, which was not generally available in the 1940s. (The first ball point pens were produced in the 1940s but they did not become generally available until the 1950s.) Reporters were unable to reach out to Otto Frank for questions as he died around the time of the discovery.[80]
However, the ballpoint pen theory has mostly been discredited. There are only three instances where a ballpoint pen was used in the diary: on two scraps of paper that were added into the diary at a later date (the contents of which have never been considered Anne Frank's writing and are usually attributed to being Otto Frank's notes) and in the page numbers (also probably added by Otto Frank while organizing the writings and papers).[81][82]
