It threatens to be the most explosive ‘lost diary’ find since the supposed discovery of the Hitler diaries were announced to a frenzy of worldwide interest 27 years ago.

For the diary that has been unearthed in an Oxfam charity shop in central Oxford, and purchased for 95p, will put to flight everything we have ever believed about the most famous extinct species — the Dodo.

The diary, written 300 years ago by an Oxford science student, shows that a Dodo was alive and well in Oxford during the 17th century.

The tatty and torn little book, that came close to being lost forever, also provides an hilarious account of how this kindly student managed to keep the last Dodo in England as a pet.

Keeping it in secrecy, the young scientist faithfully recorded the Dodo’s every move, as well as the reactions of all his friends and acquaintances.

While recognising the bird’s rarity, the student had no idea that his pet might have been the last dodo to have walked upon the earth.

But now the whole remarkable story can be revealed, with the publication of a diary that really must be seen, to be disbelieved.

A Dodo at Oxford: The Unreliable Account of a Student and His Pet Dodo (Oxgarth Press £12.99) goes into the shops later this month.

With serious doubts about its authenticity already being raised in literary and scientific circles, The Oxford Times met the man behind the find that will shake the theory of evolution — or at least the sides of his readers.

Michael Johnson, 44, is the co-author of two local guide books, The Heart of Oxford, published in 1999 and The Pocket Guide To Oxford, published earlier this year.

Ten years ago he founded his own publishing company, Oxgarth Press, in Chipping Norton, where he lives with his wife, Jane, and their nine-month-old daughter.

But his main employment is as a book designer with the Oxford University Press. So, he is a man who recognises literary gold when he sees it. He tells me the book that purports to be a diary of an un-named Oxford student, writing in 1683, re-emerged by complete chance, when he and his late friend Philip Atkins visited a charity shop.

“We came across it whilst browsing in the Oxfam bookshop on St Giles. It claims to be an Oxford student’s observations on what may well have been the last Dodo to have lived. Sensing something special, we promptly bought it for 95p,” he recalls.

That was back in March 2008. The assistant in the shop was able to throw a little light on how the diary ended up in the bargain book box just inside the shop’s front door, where it sat amongst cookery booklets and joke books.

A dirty brown paper package tied up with a bootlace had apparently been dropped off with old books by a man just a few days before. When the wrapping was removed, the little book was revealed. “It was battered, fusty, interleaved with a bizarre mixture of additional items, and without its binding,” says Mr Johnson.

Realising its potential worth, the two men placed an advertisement in The Oxford Times, which we can verify appeared in the personal messages columns in the edition of March 14, 2008. The intriguing message said: “Did you donate books, including a diary, to a charity shop in St Giles on 29 February? Please meet at 1pm on March 28 at the Martyrs’ Memorial. I shall carry a red balloon.”

Sadly, only a group of American tourists who had lost their guide turned up. “It is a mystery and a disappointment to us that we have failed to find any record of the diary in either the Bodleian Library in Oxford, or the archives of the Oxford University Press.”

By now Mr Johnson, respected OUP figure that he is, could detect my nervousness about this dodo scoop of the century.

I pointed out that he was talking to a man who was halfway through a biography of Hugh Trevor-Roper, the great Oxford historian, who had ‘authenticated’ the Hitler diaries and spent the rest of his life regretting it.

Even close friends had begun doubting the authenticity of the diary of this mystery student, who inherits a Dodo and keeps it in his rooms, admitted Mr Johnson.

But passing me a copy of A Dodo in Oxford he points to the fact that every page has been photographed and reprinted to enable readers to judge for themselves.

And what’s this on the cover? A glowing endorsement from Philip Pullman, the author of His Dark Materials.

“A masterpiece,” writes the great Oxford author, “full of wit and fantasy”. There is no doubt that, even if you decide to catagorise A Dodo at Oxford as another literary hoax, it is altogether funnier, warmer and better written than the ‘diaries’ of Hitler, Mussolini and Jack the Ripper combined.

As you read the photocopied pages, you realise that fake or not, this is a real Oxford book that belongs to the tradition of Alice in Wonderland, with its mad characters, flights of fantasy and, of course, references to a forgotten Oxford. The diary begins with the student coming to terms with the fact he has inherited a Dodo, following the death of its previous owner, a drunken Dutchman, who drowns in the river near Magdalen Bridge. Thus begins a saga that somehow marries the world of 17th-century science with Monty Python. Being a student of science he is soon undertaking experiments in his rooms, off the High Street.

“Dodo dropp’d like a stone, rebounded from the bed with great force, knocking Mr Tompkyns downe where he stood watching. Neither suffered great hurt, except in dignitie. Demonstration: dodo lacks natural proclivite for flight.”

The pet Dodo does little to improve relations with his landlord. “Dodo has batter’d a hole through the wall to reach the pigeons and fowles in the next-door room. It would not stopp and was stuck halfway,” records the diary.

The diary entries are annotated by Mr Johnson and Mr Atkins, his co-editor, from Stonesfield, who died from cancer last year, aged 59.

Mr Atkins had formerly worked at the OUP, and the two men produced the guide books together.

Mr Johnson said his friend would never see the book published but he treasured the fun they had working on their last project together.

“We used to have enormous fun playing around with ideas and things that amused us.

“I hope people think that there is a chance that it could be a genuine diary from the 17th century.

“What interested Philip and I was the idea of trying to decide if it is fake. I love the idea of allowing people to form their own views about its authenticity. That is one aspect of the book we wanted to leave slightly open, because it plays a considerable element in the actual book, and how people read it."

The pair put considerable effort into studying 17th-century type sizes and there are extensive notes clarifying the language used by the diarist, with explanations of 17th-century life in Oxford covering duelling, apothecaries, pub games and the real-life figures of the day, such as Christopher Wren.

And the reader will certainly learn a good deal about the flightless bird, which became extinct in late 17th century soon after Europeans arrived on the shores of Mauritius, while challenging the image of a weird, dim-witted Dodo.

Mr Johnson is hopeful that further volumes of the diary will one day eventually re-emerge.

“Friends urged us to show it to experts before going to publication. Perhaps we will regret the decision to go to publication.

“We will leave it for the wider world to decide.”

But what fun the world is going to have making up its mind.