In his dusty back office at the British Museum, John Curtis sat in slack-jawed disbelief. Down a crackly telephone line, an elderly man with a broad Bolton accent was describing three stone objects that had fallen into his possession, after apparently lying neglected in a garage for decades. The relics had battle scenes carved into their cracked surface and, according to the caller's story, had been bought by his father at a car-boot sale years before.
Curtis, one of Britain's foremost antiquities experts, felt as though he'd just been parachuted into one of the more colourful episodes of Lovejoy, or even Indiana Jones. It was 2005, the art market was booming, and from the caller's description Curtis had stumbled upon a rare and important discovery: Assyrian reliefs that (depending on their condition) could be worth tens or even hundreds of thousands of pounds. Curtis cleared his throat, and urged the man to bring the spoils to London for further identification.
Days later, another man – the caller's son – drew up outside the neo-Classical facade of the British Museum. Driving a modest car, he was, observers later claimed, "an everyman" who wore an inconspicuous sports jacket, tie and brown shoes, and complained of traffic on the M1. Curtis, for his part, was so excited by the relics the man carried that he showed the traveller the rest of the institution's collection of similarly rare Assyrian reliefs and agreed to take the recently discovered items to Bonhams, with a view to purchasing them for the museum's collection.
Thankfully, for Curtis at least, the sale never came to pass. A few months later, he started to smell a rat about the authenticity of the artefacts, and called in the police. Scotland Yard, in turn, revealed that the "everyman" offering him items for sale was a suspect in one of the biggest and longest-running art-forgery cases in history. His name was Sean Greenhalgh, and along with his 84-year-old father, George, and his mother, Olive, 83, he was suspected of having spent almost two decades creating fake paintings, sculptures and artefacts in a council house garden shed.
At a subsequent trial, it emerged that the Greenhalghes, who became known as the Bolton Forgers, had copied works by LS Lowry, Paul Gauguin and Barbara Hepworth. Among their victims had been Bolton Museum, which paid £440,000 for one of their phoney Egyptian statues (its experts believed the object dated from 1350BC). All three admitted to defrauding art institutions between 1989 and 2006, and pleaded guilty to conspiracy to conceal and transfer £410,392.
Last month, Sean Greenhalgh was sent to prison for four years and eight months. His mother received a suspended sentence; his father's case was adjourned while medical reports were prepared. Police experts said that in 17 years, phoney artworks worth £10m had been produced at the family's home in Bromley Cross. Scotland Yard described the eccentric Greenhalgh family as history's most diverse art forgers.
The Bolton Forgers might have briefly captured public imagination. But with the art market at the peak of its biggest financial bubble in history, they are likely to represent the tip of an enormous criminal iceberg that measures its annual turnover in billions of pounds. According to European police experts, as much as half the art in circulation on the international market could be forged – and a large proportion of those forgeries goes under the hammer in London.
Scotland Yard now has a dedicated full-time unit charged with tracking forged and stolen artworks, and says that arrests are at an all-time high. Indeed, barely a year goes by without another high-profile case involving works that have deceived experts despite having been knocked up in someone's back room.
In 2006, Robert Thwaites, a 54-year-old painter from Staffordshire with no formal training and failing eyesight, was sentenced to two years in prison for selling phoney Victorian oil paintings to finance his son's education (his victims included the gallery owner Chris Beetles and the Antiques Roadshow expert Rupert Maas). In a search of his home, police found an invoice for The Art Forger's Handbook, as well as genuine 19th-century newspapers that were used for backing the fake paintings.
Thwaites was by no means the most prolific of the recent forgers to appear in court. In 2004, a New York art dealer called Ely Sakhai was convicted of a series of frauds after identical Gauguin works appeared at rival auctions. His 15-year career had seen him flooding the international market with remarkably convincing fakes of Impressionist, post-Impressionist and Modernist masters. After being convicted, he agreed to pay more than $12.5m (£6.2m) to collectors who had bought forgeries from him.
On paper, the motives of the "big guns" of the forgery industry seem simple: profit. In reality, they can be a lot more complex. John Myatt, described as the greatest art faker of the 20th century after being convicted in the 1990s of creating bogus Renoirs, Picassos and Modiglianis, claims to have been at least partially driven by a perfectionist's desire to create near-perfect art. Since being released from prison in 2000, he has (if you will pardon the pun) forged a successful career as an artist in his own right. His paintings now sell for up to £50,000.
Thwaites, for his part, is also now also a successful artist, his reputation buoyed by a judge's description of him as "remarkably talented". After his release, he described forgery as a "risk" that he took in order to make the most of his talents. "I was pragmatic enough to realise that it could all go wrong and that if it did go wrong I would be punished," he said. "I deserved it. I wouldn't do it again. But if I can use the notoriety, why not? I love to paint... and I am very good."
Certainly, the profession of forgery has a long and glamorous history, captivating the media and filmmakers for decades. One of the most famous proponents was the Dutch painter Han van Meegeren, born in 1889. He focused on Vermeer, and produced a "Christ at Emmaus" acclaimed as authentic by the eminent art historian Abraham Bredius in 1937 before being sold for $6m. Unluckily for both Bredius and the artist, Van Meegeren was exposed after his arrest for selling one of his "Vermeers" to Hermann Goring. After being found guilty of forgery, he died of a heart attack.
Equally famous in the forging community is Elmyr de Hory, the subject of a biography by the American writer Clifford Irving; Irving's book formed the basis for Orson Welles' last film, F Is for Fake, in 1975. The artist claimed to have successfully forged a thousand Chagalls, Matisses, Modiglianis and more.
Yet Van Meegeren and De Hory are dwarfed in scale by today's million-pound forgers. Indeed, experts say that forgery could be the biggest running sore to rock the art industry since the price-fixing scandal that saw Alfred Taubman of Sotheby's jailed in 2002 for colluding with Christie's to fix commissions. The auction houses are quietly burying their heads in the sand. Although police forces are throwing unprecedented resources into the battle against forgery, no major auctioneer was prepared to talk to The Independent in relation to this article.
They may not be able to stay quiet forever. Last week, Myatt resurfaced with a Sky TV series called Mastering the Art, which lifts the lid on some of the dirty secrets behind his lucrative former trade. It provides more evidence, if any were needed, that forgers may now have the upper hand. But who are these people? And how have so many of them managed to get away with it for so long?
Vernon Rapley, the head of Scotland Yard's Arts and Antiquities Unit, is on the front line of the battle against forgery and other art crime. His officers are focusing their attention on a variety of audacious new scams, which variously take advantage of the influx of Russian wealth into the capital and the rise of internet technology. Criminals have created "mirror" websites of famous art galleries in London, posting artworks as for sale and pocketing the proceeds; others post bogus application forms for jobs in the fiercely competitive art world and state that a stipend is needed for application. The scams can take in the great and the good: indeed, unauthorised prints by the headline-prone graffiti artist Banksy, some with forged signatures, were recently put for sale on eBay.
Rapley is also receiving intelligence relating to the influx of Scandinavian works touched up by forgers to make them out to be Russian masterpieces; this presumably appeals to the "oligarch contingent" of Russian businessmen flocking to the pricier districts of the capital to thrive off its prominence on the world financial stage.
"Anywhere there is money and an interest, criminality will follow," says Rapley. "We are getting intelligence that artworks by Russian artists are being reproduced. Works that appeal to Russians are being sold. I do think at the moment there is a culture in art that dealers just make a vague assessment [of an object's authenticity] and pass the problems on. It's easier for them to say, 'I don't think it's right' than to go to the police."
Rapley, who was responsible for cracking the Greenhalgh case, describes their house near Bolton as an "Aladdin's cave". It was also Rapley who labelled Sean Greenhalgh the world's most "diverse" forger: "Most forgers I've read about take on one discipline and they perfect that skill. This guy didn't. He was moving between everything from pastels to jewellery."
Dick Ellis, who headed up Scotland Yard's art unit until his retirement in 1999, says that the Bolton Forgers ought to have been brought to book years earlier. "A London art dealer had bought an artwork from the Greenhalghs in the early Nineties; he believed it was fake. But the management at the time vetoed an investigation because it didn't have sufficient priority. Two years later another object from them came to light: a silver plate they had taken to a provincial museum which was then referred to the British Museum. Partly due to the pressure of work, and due to reorganisation internally of the arts team from a squad to a unit, the case was handed over to the special operations taskforce, who twice began work on it before other work took over."
In a café on Richmond riverside in west London, Charley Hill, another former head of Scotland Yard's art unit, shelters his breakfast from pigeons' bombing raids. With an infectious laugh, he puts the problem in this way: "The ones making the money off the Russians are the fakers and forgers. All these guys in their little workshops in Antwerp, they will create the bogus stuff. And the reason for that is that big auction houses simply can't cope with the volume of art that they've been shifting."
John Myatt lives in a rambling farmhouse near Stafford with his wife, Rosemary, and their energetic dog, Henry. The walls of the house are like a living tribute to the art of forgery. Fakes are hanging everywhere: from a self-portrait of the Queen, to Rosemary clad in Edwardian dress, to fake landscapes of his family on an evening walk in the style of Joan Miró. The house is a temple to his artistic talent.
Perhaps the most disturbing images in this ex-con's domicile are those of his fellow prisoners from his time inside Brixton Prison. One shows a notorious rapist who had been "chemically castrated"; another shows the view from one of the prison wings, which Myatt had to sketch quickly before security cameras could catch him; a third shows a saucy picture hanging on the wall of a fellow inmate's cell. His versatility and constant patter are endearing.
Indeed, Myatt's story has won him widespread sympathy. When he entered into his forgery in the late 1980s, he was trying to cope with a wife who had left him and the strain of bringing up two small children. "It's one of those things that happens because it happens," he recounts now. "I'd done a small Cubist painting for the man who turned into my partner in crime. He said, 'If I can sell it, would you be interested in half the money?' I'm worried that social services will snaffle my kids. It's not until you're half a mile down the road and you think... hang on."
That man was John Drewe, a partner in crime who is considered by many to be the Machiavelli behind Myatt's crimes. Together, they produced and sold more than 200 works of art as "genuine" between 1986 and 1994. Myatt tried his brush at everyone from Monet to Picasso, Chagall to Klee, and sold the results, sometimes for tens of thousands of pounds; a "Giacometti" went at auction in New York for $300,000.
Towards the end, however, Myatt got cold feet, or "an attack of morality" as he now puts it. At the same time, however, Drewe's ex-wife had gone to the police with incriminating documents. Soon afterwards both Myatt and Drewe were dragged in by the police. "When I was arrested I had not been committing for a year. I thought I could work afterwards and retire. It was about four days before I was going back to school."
However, Myatt's post-prison fame has enabled him to start a his own "genuine fake" business; they now sell for up to £45,000; Clive Owen is rumoured to be playing him in a film.
He still seems unsure about whether, morally, he has done anything wrong.
"Two minds is the place to be," he says. "One mind says you're producing something that is beautiful and that people flock to see and are proud to own. So why don't the galleries sell expensive artefacts and replace them with identical copies? Then there's the fact that you can see a Leonardo and stand centimetres away. Though all these added frissons seem to be culturally acquired. We are forced into a reverence of things that does not seem right. With these fakers, no one is dead."
The moral remains as it ever was: buyer beware.