Cambridge University Library, which long thought it had misplaced the cultural treasures, has now made a public appeal for information on their whereabouts.
Now, the library has said it believes the notebooks were most likely stolen, and it launched a public appeal for any information about their whereabouts on Tuesday.
The notebooks were first listed as missing in January 2001, and staff at the library had long thought they had simply been misplaced among its vast collection of around 10 million books and objects.
Dr. Gardner said library protocols at the time the books first went missing were very different, and new strong rooms, specialist reading rooms, CCTV monitoring and enhanced security have been added since 2001.
Detective Sgt. Sharon Burrell of the Cambridgeshire Police said the stolen items had been reported to Interpol and she hoped publicizing the potential theft “jogs someone’s memory,” resulting in information that can secure their return.