John Drewe, self-styled professor and nuclear physicist, plotted an international fraud that took in some of the art world's leading galleries and collectors. Among his victims were the Tate Gallery, Sotheby's, Christie's and the families of 20th-century artists.
Drewe's activities were first revealed three years ago in an investigation by The Independent. Since then the paper has learnt that Drewe had previously passed information about art fraud to the police and that he had contacts in the Mafia.
He was convicted yesterday, after a five-month trial, of seven charges, including conspiracy to defraud. A co-defendant, Daniel Stoakes, 52, was acquitted.
Southwark Crown Court was told that Drewe, 50, hired John Myatt, an unknown artist, and encouraged him to fake works in the style of Ben Nicholson, Marc Chagall and Alberto Giacometti. Myatt used a mixture of household emulsion, lubricating jelly and the contents of a vacuum cleaner to "age" the paintings. Drewe added authenticity by making frames from old wood and signing them with the artists' names.
Drewe's scheme relied on creating histories or provenances for these paintings. Over a period of months, he set about substantially altering and supplementing Britain's art archives to include details of his non- existent "works". At one point, he even spent pounds 20,000 to become a Fellow of the Tate Gallery, allowing him access to its vast records, which he set about changing. He also faked catalogues from non-existent exhibitions that had "displayed" the paintings.
Although Drewe was charged in connection with just nine paintings, police believe that he and Myatt produced up to 200 works over a 10-year period, which were sold in the US, Middle East and Europe.
While Myatt was paid just pounds 250 a time, Drewe - using a number of middle- men -sold the paintings for up to pounds 100,000. Police believe he may have profited by up to pounds 2m.
Detective Sergeant Jonathan Searle of the Metropolitan Police's organised crime group said yesterday: "This is the biggest contemporary art fraud the 20th century has ever seen. It was brilliantly carried out."
But the case has also highlighted a number of failings in the security of many of Britain's galleries and auction houses. Both the Tate and the Victoria and Albert Museum have since tightened their procedures.
One gallery owner said: "The trouble is that if the paintings are worth less than pounds 100,000 no one bothers to check out their histories. They call themselves experts but they are just lazy."
When he opened the case, John Bevan QC, for the prosecution, told the jury it was dealing with a "clever, intelligent and articulate" fraudster. Drewe even told detectives there was no point in listening to Daniel Stoakes, as he had been in and out of psychiatric hospitals - what he did not say was that the man was a psychiatric nurse.
Drewe's ability to deceive was so feared by prosecution and police that after he sacked his top-flight legal team on day two of the trial - because he thought he could do a better job - he was forbidden to examine original case documents except under the closest supervision.
Drewe, from Reigate in Surrey, and Myatt, 53, from Staffordshire, who had previously admitted his involvement, are to be sentenced on Monday.