Many bestselling and award-winning travel writers have turned out to be distinctly unreliable narrators. Should we file their books under fact - or fiction? And do readers really care?
Made-up characters, placing themselves in the thick of it when they were not actually there, embroidering reality - these are just some of the charges that have been made against writers including Patrick Leigh Fermor, Norman Lewis, and Bruce Chatwin since their deaths.
Perhaps I am naive, or my career as a hack has turned me into a clunking literalist. But I find myself thinking, if these writers made things up, do they forfeit our trust altogether?
Maybe this diminishes them, and their books, to the point where we no longer want to read them.
"A lot of people use travel books as guides, and the idea of fictionalising - making things up - misrepresents a place and is a disservice to a reader," says Paul Theroux, American travel writer and author of The Great Railway Bazaar.
"Invention is not acceptable."
So what are some of these crimes against truth-telling?
In Norman Lewis's book A Dragon Apparent, he gives a vivid, first-hand account of a Viet Minh bomb going off outside a Saigon cafe in the 1950s.
Placing himself at the centre of the action, he adds: "I went down to see if there was anything to be done, but already the wounded were being tended."
But according to his biographer, Julian Evans, this explosion took place outside Saigon, and happened three weeks after Lewis visited.
In another of Lewis's books, Voices of the Old Sea, he describes meeting a Spanish aristocrat, Don Alberto. But this distinguished Spanish senor was fictional, and was probably based on four or five different people that Lewis had encountered.
The late Patrick (Paddy) Leigh Fermor was a war hero, best known to his readers for walking through pre-war Europe as a foot-loose teenager. But he only got round to writing about this journey decades later.
On top of that, he lost almost all of the notes he made.
"It was the best thing that ever happened to him. It set him free," says his biographer Artemis Cooper.
And free he was. In one passage in Between the Woods and the Water, Fermor describes a horse ride across the great Hungarian plain. But Cooper realised from her knowledge of an earlier draft that Paddy was entirely horseless at that point in his trek.
"Paddy said: 'Ah yes, well, I thought everyone would get tired of me trudging along so I put myself on a horse for a bit - you won't let on will you?'" she recalls.
Our favourite strolling authors, it seems, might have had feet of clay.
But does it matter? Don't their polished yarns improve on reality, by giving the reader a better insight than more workaday and ambiguous "truth" can offer? And aren't their worked-up stories simply more fun, better page-turners?
Perhaps we need a definition of travel writing. After buying a guide book, for example, you hope you have invested in complete accuracy.
"You don't want to turn right when you should turn left," says Tony Wheeler, co-founder of Lonely Planet travel guides.
Travel literature, where someone tells you about a trip they have made, "doesn't need accuracy in the same way, there can be an element of fiction to it", Wheeler argues.
"With Bruce Chatwin, for example, you knew from the very start that you were reading something that was somewhat a work of fiction."
But it seems not everyone understood that the acclaimed Chatwin preferred to err from the straight and narrow. A German film maker wanted to adapt his book Songlines, which was inspired by his travels in Australia. But the director struggled to follow what she took to be Chatwin's route across the outback.
As his widow, Elizabeth Chatwin, explains. "He changed the names of places, and it's not consecutive. It was not a proper travel book."
Chatwin's biographer Nicholas Shakespeare says he did not like the label "travel writer", and even had Songlines removed from the shortlist of a travel book award, insisting it was a novel.
Perhaps the author really did set out to write fiction all along. It really isn't as simple as a moral fork in the road - truth or lies. Some writers negotiate this territory by insisting there's no such thing as a straight, factual account of anything.
Iain Sinclair, author of books such as Hackney, That Rose-Red Empire, says: "Editing and slippages of chronology are what make something fiction. There is no absolute account. Non-fiction is entirely a myth. There is only the absolute present moment."
For my part, I've come to the conclusion that what matters to me are the writers. It's their company that I enjoy. By contrast, their journeys are MacGuffins, A-to-B devices. In the final analysis, they're secondary.
What the writer does, what happens to him, is interesting because of how it develops my relationship with him as a reader - even when, or perhaps especially when, he makes things up.
Of course, I only know about that thanks to assiduous biographers, by and large. But their revelations haven't caused a final breach between me and these writers.
They have brought me to a greater, albeit different, understanding of them.