Illustration of ‘old sultan’ by surrealist artist found at a house clearance sale by Cambridge antiques dealer

To the untrained eye, it looks more like an alien has landed on Chewbacca’s head than a masterpiece by Salvador Dalí.

But the watercolour and felt-tip painting – bought two years ago for £150 – has been sold at auction for £47,700, after it was identified as a lost illustration of an “old sultan” by the great surrealist artist.

The piece was found at a house clearance sale in Cambridge two years ago by a local antiques and art dealer, John Russell*. During the sale of the contents of a London garage, he spotted Dali’s signature in the bottom-right corner of the picture and stickers from Sotheby’s on the back.

He thought the painting might be a fake but decided to bid for it “on the spur of the moment”. Only one person bid against him, dropping out when Russell offered £150. “It was a once-in-a-lifetime feeling,” he told the Guardian.