He bought them for pounds 4 each. 'I got pounds 100 worth from the boyfriend of a girl I know,' he said. 'I don't know where he got them, but he had lots. You don't ask stupid questions.
'It's surprising how many pubs don't check them, but staff are getting more wary and it is becoming difficult. Once I get a drink I finish it quickly and leave in case the note is spotted.'
Counterfeit notes are a persistent problem, according to the Bank of England. It refuses to put a face value on the number of forged notes it recovers but a spokeswoman said that modern laser printers and photocopiers had made forgery easier, although the paper was always difficult to imitate. 'One reason for introducing the new bank notes was to make counterfeiting more difficult,' she said.
A specialist police unit, the National Office for the Suppression of Counterfeit Currency, monitors the places where forged notes appear, passing intelligence to regional crime squads. Detective Inspector Henry Kirkup said: 'Over the past three years there has been a large increase in counterfeit currency throughout the country. There are occasionally peaks in an area, but there is no overall pattern.'
He said there was a strong indication of links between counterfeit currency and drug dealing. Both use well-developed distribution systems. Large-scale production of notes was handled by organised crime. 'People have got to be more vigilant. If people are shown a forged note, 99.9 per cent will spot it.' The main security features are the quality of the printing and the paper, the watermark and the metal strip.
Gangs tend to target specific areas, which are flooded with pounds 20 notes. After the Appleby Horse Fair this year, a large number of forgeries turned up in Penrith, Cumbria. At Cambridge railway station, the ticket machine no longer accepts notes because of the number of fakes tendered. A woman in Yeovil, Somerest, recently received a forged note from a bank's cash machine.
The 'quality' of fake notes is a good selling point for salesmen offering pounds 70 machines to spot imitations. Some salesmen make a purchase with a forged note and return later to ask the business whether it has had any problem with fakes. The salesman then reveals he has just passed a dud.
Jason Williams, sales manager at the Cardiff Volkswagen Centre, bought two of the ultraviolet machines and has since identified more than pounds 11,000 worth of forgeries. 'We tell the customer and they presumably go away and try them elsewhere; nobody wants to write off the money.'
There is no compensation for handing in forged notes. The Bank of England explained: 'In every crime somebody has to suffer and it is whoever is given the forged note.'
One Bristol publican who recently took pounds 30 in forged notes in two days said: 'I can't afford to lose that money. I put them in bundles of notes when I go to the cash-and-carry.'