According to INTERPOL, between $4 billion and $6 billion in art is stolen every year throughout the world, much of it turning up on the U.S. art market. To cope with this global crime problem, the FBI has deployed a powerful law enforcement resource.

Her name is Lynne Chaffinch. Since 1997, she has run the FBI's art theft program, which among other things maintains a computer database containing files on more than 100,000 pieces of stolen art. And, as the bureau's only certifiable art expert, she does it all by herself. "You're looking at the art theft program," she said, indicating herself as she sat in her modest office at FBI headquarters in Washington.

An art and archeological scholar who came to the FBI from her position at Monticello, Thomas Jefferson's Virginia home, Chaffinch is not an FBI special agent. She packs no heat, and is not empowered to make arrests. But she doesn't need to, for she has all 56 FBI field offices, 400 smaller offices and 11,300 special agents at her disposal in dealing with art cases. And, when they or other law enforcement agencies need assistance with cases involving stolen art that break in their local jurisdictions, they call Chaffinch. The same goes for foreign governments who think stolen or looted art may have turned up in or been bound for the U.S.

Chaffinch keeps track of what stolen art is out there whether it's 3,000-year-old Chinese terra cotta heads or a priceless Vermeer painting, such as was snatched in the 1990 robbery of Boston's Isabella Stewart Gardner Museum.

Expertise that agents don't have

"Basically, there's not a single FBI agent assigned to art theft, not one," said Special Agent John Strong, who has worked with Chaffinch. "In five minutes, they [art experts] know I'm not one of them. Lynne's not an agent, but she can go out there [into the art world] because she was one of them. She doesn't have to fool them. . . . She's got the knowledge and the education."

Such expertise can be valuable. One piece of supposedly junk sculpture a burglar sold to a pawnbroker for $40 turned out to be an Alexander Archipenko work worth $600,000.

Unlike the art theft insurance agent Rene Russo played in "The Thomas Crown Affair" movie, Chaffinch does not spend a lot of time wearing designer clothes to posh gallery openings or on jaunts to exotic locations. Instead, she is most likely to be found at her computer. She directs investigations, coordinating various agents' efforts, and pursues leads on her own. She also serves as the in-house program analyst for the FBI's stolen jewelry and gem theft investigations. But once in a while she does get out, such as the time she went out on a search warrant. An informant had told the bureau there was some valuable art on a suspect's premises, and the field agents needed Chaffinch's expertise to determine whether that was true. "The informant was embellishing," Strong said. "He didn't know art from a lawn jockey."

The daughter of an Air Force colonel, Chaffinch was born in Texas and grew up on or near military bases all over the world. She graduated from the University of California-Davis with majors in archeology and anthropology, and earned her master's degree in museum studies from San Francisco State University. Before the FBI, she worked as an archivist, cultural anthropologist and in other arts and antiquities related positions for the Smithsonian Institution, the Los Angeles Museum of Western Heritage, the Oakland Museum and Monticello.

She read about the FBI job in a museum newsletter and responded to it on impulse, encouraged by some detective work she'd done for her sister, a Los Angeles-based customs agent. "She called me and said, `You know, I've got these [stolen] pieces and I don't know who to go to about them,'" Chaffinch said. "I helped her find the right experts and where the stuff might come in and where it might hit the art market. She was able to do surveillance on the warehouse and recover the objects. I thought, `That's really neat. That's a cool thing to do.' So when I saw this job listing, I thought, `I've got no chance to get it but I'm going to send in a resume.'"

Though there are occasional high-profile museum heists like the Gardner case, most of the art stolen in the U.S. is taken from residences, Chaffinch said, and usually the perpetrators don't know the value of what they're taking. "Not that there aren't more sophisticated thieves out there," Chaffinch said, "but generally the art thief in the U.S. is the same guy who will steal your car or your TV." The problem for the FBI is that the U.S. buys 60 percent of all the art sold in the world, and a lot of that art is stolen.

American galleries are often suspicious of prospective sellers of art, Chaffinch said. "But they won't call law enforcement because they're afraid their customers will fear that if they have any suspicion, `they'll call the cops on me.'" Chaffinch's data file is a big help in that respect. It even contains reports of stolen classic cars, including a rare decades-old Aston Martin taken in Florida that was originally used in an early James Bond movie. "It's still out there," she said.

How stolen pieces are disguised

Because there's no way yet for a customs agent to tell on the spot that, say, a Picasso painting might be stolen, it's often hard to stop the importation of purloined art in the U.S. If the thieves try to hide the art or fail to declare it, however, agents can grab them for customs violations. Sometimes thieves go to great lengths to disguise their art, especially statues. "In a case where some Egyptian items were taken, what the thieves did was dress them up to look like cheap souvenirs," Chaffinch said. "Then, when they got them to the U.S., they took everything off, and, boom." After the Gardner burglary, Sen. Edward Kennedy (D-Mass.) and others gave Chaffinch and the FBI a hand by getting legislation passed in 1994 to make a lot of art theft a federal crime.

Now, if a piece of art is stolen, is worth more than $5,000 and is more than 100 years old, it's a federal crime to possess it. If it's worth more than $100,000, the age doesn't matter. Chaffinch's job may be considered one of the most exciting to be had in the art world, though she confesses she spends most of the time at her computer, "going `arggghhh.'"

But she's happy.

Said Strong: "She doesn't want to become an agent Strong, "because then she'd be like the rest of us." "I'd be shipped off to do counterterrorism somewhere," Chaffinch said. "I'm already where I want to be--in my own little kingdom here."

A RARE canvas painted on both sides by L. S. Lowry, stolen from the home of a retired opera singer and presumed lost for ever, has reappeared eight years after the theft to the delight of art experts.

Scenes entitled House in a Park and The School Gates were painted on the two sides of the canvas by the Manchester-born artist, famed for his industrial landscapes depicting the north of England in the early 20th century.

The picture was stolen from the home of Anna Pollak, a former mezzo-soprano who was a star at Sadler's Wells during the 1940s. By the time Miss Pollak died four years ago, the police had all but given up the search for the stolen artwork.

Last year, however, the canvas appeared for sale at Bonhams, the auctioneers. The recovered canvas, extremely rare because both sides were painted, was worth just £4,000 when it was stolen. It was sold last November for £42,000. It was a bequest of great sentimental value from Miss Pollak's lifelong companion, Erica Marx, a great-granddaughter of Karl Marx, the communist philosopher.

Presenters from BBC's Antiques Roadshow are teaming up with undercover police officers to expose crooked dealers and counterfeiters. Alastair Dickenson, the show's silverware specialist, accompanied plainclothes officers when they raided an antiques dealer from Chester and found a bag containing 16 identical counterfeit silver snuffboxes and eight false tortoiseshell-plated antiques. Mr Dickenson, 49, spotted that the boxes made in the Victorian style had fake Georgian hallmarks. Last week Alan Shindler, 59, who owns the shop, began a six-month jail sentence for selling fake goods.

Mr Dickenson said: "I was asked by trading standards officers to get involved as they started to close in on the fraudsters. They paid me to go with them into the shop and examine the wares and I found that they were obvious forgeries. The police do seem very keen on hiring the services of recognised experts. The Roadshow does put us in the public eye and so it is natural that they ask us to help them out."

Peter Nahum, one of the programmes's fine art specialists, helped to smash one of the biggest peddlers of counterfeit art ever to operate in Britain. He helped police identify fakes among a number of paintings sold as works by Marc Chagall, Georges Braque and Paul Klee which had been sold by a dealer, John Drewe. Last week he said that police were seeking the help of expert witnesses more and more as they close in on counterfeiters: "Art fraud is the second oldest profession in the world - but it is growing at a pace. The number and quality of copies are increasing so quickly."

Bill Harriman, who has regularly assessed firearms on the show since 1985, has also been asked to give expert testimony by the police and trading standards departments. As well as appearing on the programme, Mr Harriman is firearms officer for the British Association for Shooting and Conservation.

Recently he was commissioned to provide an opinion on whether a sword sold by a Brighton antiques dealer, described as coming from the Nazi era, was genuine. He said: "In this case my opinion was commissioned by the defence, but it makes no difference because I am completely impartial and would give the same opinion whoever asked for it. The sword was definitely from the pre-Nazi era but it had two SS lightning-style initials engraved on it.

"The antiques dealer was being accused of selling a fake but in my opinion the SS flashmarks were put there during the Nazi era. They were consistent with others and were to a high standard, so the sword was genuine. Trading standards dropped the case."

He is also regularly asked to judge whether firearms seized by the police are legally held. Six months ago, he was asked by police in Wales whether a handgun was legally held since the 1997 ban was imposed. "I said I thought it was legally held and, what's more, qualified as an antique so was exempt from the ban."

The show's experts have even been used by thieves to evaluate their hoards. Last month one suspect, described as a "military gent" with a handlebar moustache, was told his silver antiques were worth £20,000 when he took them to the Roadshow, being filmed in Middlesbrough. Police later realised he was a conman, valuing stolen goods.

JEREMY PAXMAN opened a mystery parcel yesterday and found the missing Enigma cipher machine, stolen six months ago from Bletchley Park, the home of Britain's wartime codebreakers. The presenter of Newsnight and University Challenge did not at first realise the bonus that was waiting for him in the BBC offices. The hefty cardboard package, sent by Royal Mail special delivery, had been lying unopened for days before a colleague pointed out it was addressed to him.

Paxman said: "As soon as I opened it I realised what it was. It looks as though it is authentic. It's got the G312 code on the back. I haven't a clue why they sent it to me. As far as I know I haven't got a reputation as a receiver of stolen goods. I'm delighted to be able to return it to its rightful owner. They are very poignant machines. I think what they did at Bletchley Park during the war was quite outstanding."

The device, which was posted in a wooden box with a leather handle and wrapped in three layers of packing and bubble wrapping, has yet to be authenticated by Bletchley Park. It was sent without its three main rotors, the key enciphering component, and the Bletchley Park Trust was told these would only be handed over in return for £25,000 compensation. The rare, four-rotor version of the wartime machine used by German military intelligence is worth £100,000 intact but much less without its rotors.

Christine Large, the trust's chief executive, said that the "new owner" had contacted her yesterday to give his instructions for a handover of £25,000, which he claims was paid for the machine, in exchange for the rotors. The trust agreed to pay the ransom following a threat from a "middle-man", claiming to act for someone who bought the machine, that it would be destroyed. A British company is understood to have come forward to offer the £25,000.

Mrs Large said: "Following this act of faith by the new owner of G312, we are now attempting to put him in touch with representatives of the benefactor who has come forward with the £25,000 ransom."

A MUSEUM attendant smuggled out a hoard of rare coins in his pockets and sold them on to specialist dealers for a fraction of their true worth. Douglas Wilson helped himself to more than 150 coins , including one worth £100,000, from Perth Museum and Art Gallery, where he had worked for two years.

The thefts were discovered when management updated the catalogue of the coin collection. At Perth Sheriff Court yesterday, Wilson admitted stealing coins worth £158,715. Sentence was deferred for reports.

Wilson, 42, of Perth, had keys that allowed access to locked store areas and the locked boxes where coins were kept. The court was told that between September 1999 and February last year, he often left the museum with a pocketful of coins. He sold them to dealers around the country. It is believed, however, that Wilson, who had no previous convictions, had little idea of their value and sold them for substantially less than their true worth.

Museum staff were modernising the records when they discovered that a significant number of coins had gone missing. A 14th-century gold coin, one of only five in the world and estimated to be worth about £100,000, was recovered by police with the majority of the other coins that Wilson had sold. However, coins worth about £20,000 have never been traced.

After the museum contacted police, checks were carried out on Wilson's finances and he was discovered to have cashed large cheques at a shop in Perth in the name of his girlfriend, Ida Coghlan, 43. Ms Coghlan was charged with reset of the coins. The case was dropped by the Crown.

Michael Taylor, Perth Museum's head of arts and heritage, said after the case yesterday that a security review had taken place at the museum. "We were obviously very disappointed because in a job like this there is a tremendous element of trust," he said. "It is a very responsible position in terms of having access to a valuable asset which belongs to society, and that position was abused by Douglas. But I am glad to say that the majority of the coins have been recovered. "Given the nature of museums there is no way you can keep staff away from the collection and we did the usual employee record checks."