Twenty-five years ago, one of the most contentious pieces of evidence in the Jack the Ripper investigation first surfaced. It was a photo album or scrapbook with the first 48 pages missing. The next 63 pages contained a handwritten narrative that concluded with the chilling words, “Yours truly, Jack the Ripper.”

The contents of the narrative make it clear that the author is James Maybrick, or someone pretending to be him. Maybrick died in 1889, the year after the Ripper murders. His wife, Florence, was convicted of murdering him and sentenced to death but reprieved.

Over a century later the diary was presented to a literary agent by a scrap metal merchant, Michael Barrett, who claimed that a friend gave it to him in a pub. Barrett claimed afterwards that he forged the diary then recanted that confession. His wife said that the diary had been in her family’s possession for some time. This dubious provenance cast doubt on its authenticity, although tests on paper, ink and handwriting were inconclusive.

Next month sees the publication of a new book, by the diary’s owner, that provides a same-size, colour, replica and an assessment of events since the discovery. This apparently includes evidence that the diary was found inside the Liverpool house of James Maybrick.

The diary of Jack the Ripper is either a hoax or a genuine confession. If it can be established that it came from the house of the alleged author then we have to consider the logical possibility that he was involved in its composition.