Back in September 2003, it had seemed such a bargain - a 3,300-year-old sculpture of one of the daughters of the Pharaoh Akhenaten and Queen Nefertiti, valued at £1m, but offered to the Bolton Museum, Art Gallery and Aquarium at the knockdown price of £440,000 by an anonymous local vendor.
The British Museum inspected the piece; the auction house Christie's handled the private treaty sale; the National Heritage Memorial Fund chipped in £360,000; and the National Art Collections Fund (now called the Art Fund) gave £75,000.
But now it has been revealed that the vendor was also probably the manufacturer and that the statue was given the nod by the specialists almost purely on the basis of a false provenance, the diminutive alabaster statue is casting a long shadow over the august institutions involved in the acquisition.
But the tradition of experts being fooled by fakes is as old as collecting itself. In 1990, Mark Jones, now the director of the Victoria and Albert Museum, organised the British Museum's landmark exhibition Fake? The Art of Deception. He isn't at all surprised by the Princess palaver.
'We know from an overwhelming body of evidence that in every generation, people - many of who are serious scholars and great connoisseurs - are taken in by fakes.' He adds: 'If museums in Britain are seldom taken in, it is only because they acquire very little proactively nowadays.'
Pending the police enquiry, all the players in the case of the phoney Princess must remain tight-lipped on the question of whether the experts could have done more to ascertain authenticity. But what should a museum do once it realises it has been had?
Doing nothing is an option. The centrepiece of the Imperial War Museum's recently opened London show, The Animals' War, is a portrait of Rob, the SAS collie, and his Dickin Medal for Gallantry. This is an award specifically for animals in war that was given to the dog in 1945 for 20 wartime parachute drops. But one of the surviving officers from Rob's regiment has confirmed a previous claim that the animal was just a barracks-bound companion dog who had never leapt from anything higher than a sofa.
A museum spokeswoman, deep in denial, says: 'The information included in the exhibition was taken in good faith from the Dickin Medal citation and from the testimonies of the owner's family. We will not be taking the Rob the "para-dog" material out of the exhibition.'
Acknowledging its changed status and consigning your embarrassing artefact to the gallery storeroom or a local saleroom is an option. But the idea outrages Mark Jones. 'Nothing could be less responsible than getting rid of fakes, although there is, understandably, initial disappointment on finding out they are not what they are supposed to be,' he says. 'From the museum professional's point of view, fakes are historical documents of considerable value and need to be treated as such.
'Fakes are important to understanding the history of reception of objects,' Jones explains. 'If people were taken in by these objects, it was because that was how they thought they should look. Fakes provide a valuable opportunity to see through contemporary eyes.'
Rob's faux CV tells us nothing about the historical figure, but everything about the relationship of the British people with the dog and the 1940s hunger for wartime heroes. Some likeminded collectors have sought out fakes as social history.
Henry Syer Cuming was afflicted by the mid-19th-century hunger for antiquities, and this appetite drove him to acquire several forgeries made by two mudlarks (amateur archaeologists who combed the mud of the foreshore of the Thames for treasure) - William Smith and Charles Eaton. The pair specialised in faking 'medieval' lead medallions, pilgrim flasks and figurines. Later, realising his mistake, Cuming not only owned up to being duped, he publicised the fraud and continued to collect the objects that had fooled him.
'They are quite beautiful, but not remotely medieval looking to modern eyes - and the lettering on them was gobbledygook,' says Catherine Hamilton, the collections and museum manager of the Cuming Museum in south London. The display of fakes by 'Billy and Charley' at the museum is one of its most popular sections.
In the 21st century, perhaps unreasonably, we expect our major public collections to be infallible: the final arbiters on authenticity and the gold standard in terms of scholarship. But the truth is that fakes will always be unmasked as research progresses. Some curators have taken the view that the best a museum can do is to outline the latest opinion and make the discovery process transparent.
Scientific collections do this particularly readily, perhaps because when their fakes are reattributed, scholarly embarrassment is not accompanied by a steep drop in financial value.
The aged-up skull and orangutan jaw found at Piltdown, Sussex, in 1912, were believed to be Darwin's 'missing link' by the scientific community for 40 years. Fifty years after its exposure, London's Natural History Museum celebrated the reassessment of Piltdown Man in 2003 by hosting a series of lectures and events exploring scientific fakes and forgeries.
In a similar spirit, this year the Rijksmuseum in Amsterdam commemorated the 400th anniversary of Rembrandt's birth with a show called Really Rembrandt? Rembrandt's oeuvre is a treasure trove for fakefinders, so much so that the Netherlands-based Rembrandt Research Project, established in 1968 to investigate the paintings attributed to Rembrandt, is still in full swing. Before the project began whittling, attributions numbered about 900; nowadays, that embarrassment of old masters has been edited to about 600 paintings.
Really Rembrandt? invited the public to scrutinise nine examples that were considered genuine Rembrandts by the museum at the time of their purchase, but whose authenticity fell into doubt over the years. Visitors saw what infrared and X-ray images revealed and read the opinions of the experts, and made up their own minds.
Robin Meador-Woodruff, formerly of the Kelsey Museum of Archaeology at the University of Michigan, curated an online exhibition called The Art of the Fake: Egyptian Forgeries from the Kelsey Museum of Archaeology, with a similar aim. Real and fake Egyptian artefacts were shown side by side and used to illustrate how and why museums come to be fooled by the forgeries.
The National Portrait Gallery in London used this year's Searching for Shakespeare show as an opportunity to re-examine the most famous portraits of the playwright. The results of four months of tests on the Flower portrait, a painting in Jacobean style, which bears the inscription 1609, were disappointing, although not unexpected.
Scientific analysis found chrome yellow and French ultramarine pigments that dated the painting to the early 19th century. David Howells, the curator in charge of the painting, which is owned by the Royal Shakespeare Company, says: 'It would have been lovely to find we were wrong in our suspicions, but knowing the truth and where it fits into the history of portraiture of Shakespeare, and the insight it gives into the rebirth of interest in Shakespeare in the 19th century, is more important.'
Many curators confirm the value of the counterfeit, not least as ingenious creations that hold a special allure for the public. Geoff Swinney, the principal curator of lower vertebrates and molluscs at the National Museums of Scotland, is also responsible for cryptozoology (the study of unknown creatures). He is the proud keeper of several manufactured creatures, including a hirsute trout.
A woman brought the hairy fish into the museum for inspection and relayed the tale that it had been caught in Arctic Canada, where the weather was so cold that the fish had grown fur. When told it was a spoof made by taxidermist Ross Jobe using rabbit fur, its owner took umbrage and left the museum - and the trout.
'Later, when we had thrown it out, we started getting lots of enquiries about our furry fish, and so one of our own taxidermists made another to put on display - a fake of a fake,' remembers Swinney. After the faux trout went on show, Jobe himself called the museum, utterly tickled by the story. 'He kindly offered us a genuine fake, that he had made.' Now the museum has two identical fakes - one slightly more authentic than the other.
There is still plenty of scope for the sport of fake-spotting in museums the world over. Brian Sewell, the outspoken art critic at London's Evening Standard newspaper, says: 'There's a Francia on display in the National Gallery that I'm quite certain is a 19th-century fake, and a collection in Paris, the Jacquemart-André museum, is stuffed full of fakes, particularly Botticellis. There was a positive Botticelli industry in the 19th century.'
On the other hand, Sewell says the National Gallery's prize acquisition, Raphael's The Madonna of the Pinks, for which it paid £22m in 2004, 'is absolutely not a fake'. He adds: 'It is a picture painted fairly early in the 16th century by a Florentine painter to a design by Raphael'. That's a relief, then.
Katrina Burroughs is a freelance journalist
The Animals' War at the Imperial War Museum is reviewed in this issue
The Art of the Fake: Egyptian Forgeries from the Kelsey Museum of Archaeology is at: www.ipl.org/div/kelsey/exhibit.html