Gainsborough bought at street market for pounds 85

IF YOU HAPPEN to have visited Bermondsey market recently and bought a portrait of William Pitt the Younger, the chances are it is a Gainsborough and you are sitting on a small fortune.

Mr Pitt is still missing but Gainsborough's portrait of Judge Sir John Skynner, rolled up and wrapped in a binliner, was bought in the south London market last Friday for a very reasonable pounds 85. The purchaser, an amateur art expert, also picked up a portrait of Francis Hargrave, a former treasurer of Lincoln's Inn Fields, by Sir Joshua Reynolds, for pounds 60.

Three years ago, when the pair - along with Gainsborough's William Pitt the Younger - were stolen from Lincoln's Inn Fields, police valued them at pounds 6m.

On Tuesday, when the buyer - 'middle- aged with an office job' is all the police will say - turned up at Sotheby's, Lucy Hudson, paintings specialist, recognised them immediately, valuing the Gainsborough at pounds 75,000 and the Reynolds at pounds 15,000. Within moments the innocent buyer was having his collar felt by detectives.

Ms Hudson said: 'I couldn't believe my eyes when this man pulled these two paintings from the bin bag. It doesn't happen every day that someone walks in off the street with a Gainsborough.'

The new 'owner' let Sotheby's keep the paintings. Yesterday, police went back to Bermondsey market but the seller's pitch was empty and there was no sign of Mr Pitt. Ms Hudson said that painting would fetch up to pounds 300,000 in auction. The police say it may well have been bought the same day.

On paper the recovered paintings belong to the insurers who paid out pounds 100,000 to Lincoln's Inn Fields. David Corsellis, assistant under-treasurer at Lincoln's Inn Fields, said the trustees may return the payout and take back the paintings.

But what about the purchaser's rights? A week after his bargain buys, he is pounds 145 worse off with no paintings to show for it.

However, he might be interested to learn that Bermondsey is a 'market overt', one of only 20 in Britain covered by a fifteenth- century legal loophole which says those buying goods between dawn and dusk acquire ownership or 'good title', even if they are stolen. He could fight for his ancient rights in the courts.