Two of Charles Darwins manuscripts, one of which contains Darwin’s famous 1837 ‘Tree of Life’ sketch, have been reported stolen by the Cambridge University Library, following the largest search for lost items’ in the library’s history.

The notebooks were first reported missing in January 2001 with curators recently concluding that they have most likely been stolen. For years it was simply assumed that the notebooks had “been misplaced in the vast storerooms and collections” of the University Library.

The value of the notebooks is difficult to estimate but it is thought their worth runs into the millions of pounds.

The University Library launched an appeal on Tuesday (24/11) to try and recover the notebooks. The appeal was intended to coincide with ‘Evolution Day’, which recognises the anniversary of Darwin’s publication of ‘On the Origin of Species’.

The appeal follows an extensive search, led by an “expert team conducting fingertip examinations where necessary″,  and which included “a complete check of the entire Darwin Archive, which contains 189 archive boxes.”

As part of their appeal, the University Library released a video where Dr Jessica Gardner, University Librarian and Director of Library Services, said: “I am heartbroken that the location of these Darwin notebooks, including Darwin’s iconic ‘Tree of Life’ drawing, is currently unknown, but we’re determined to do everything possible to discover what happened and will leave no stone unturned during this process.”

Gardner emphasised the importance of the public appeal in seeing that the notebooks are safely returned and urged “anyone who thinks they may be able to help to get in touch.”

She continued: “We would be hugely grateful to hear from any staff, past or present, members of the book trade, researchers, or the public at large, with information that might assist in the recovery of the notebooks. Someone, somewhere, may have knowledge or insight that can help us return these notebooks to their proper place at the heart of the UK’s cultural and scientific heritage.”

Cambridgeshire Police have been informed of the disappearance of the notebooks and the theft has been listed on the national Art Loss Register which keeps a record of missing cultural artefacts. The University Library has also taken advice from external experts in security and cultural asset recovery to help in the search.

Detective Sergeant Sharon Burrell, of Cambridgeshire Police, commenting on the time-lapse since the books were stolen and the start of the investigation, stressed that “information from the public will be very important to this investigation. We have made initial inquiries to trace their whereabouts, including contacting Interpol to place the items on their Stolen Works of Arts Register.”

Security policy 20 years ago means the procedure for reporting missing objects was very different from today where a potential theft would be reported immediately and a widespread search would commence immediately. Gardner detailed that “we [the University Library] keep all our precious collections under the tightest security”.

Professor Stephen Toope, Vice-Chancellor of the University, on the lost works, said: “Cambridge University Library is one of the world’s great libraries and home to globally important collections, assembled and cared for over six centuries, and encompassing thousands of years of human thought and discovery.”

“As a result of this appeal for help, we hope to locate the missing Darwin notebooks and restore them to their rightful place alongside the University Library’s other treasures, making them available to scholars and researchers in the centuries to come.”

The University Library will not stop searching for the notebooks, however, with over 210km (130 miles) of shelving this will be a feat in and of itself.