A sketch scribbled on a young woman's autograph book 50 years ago by Bradford artist David Hockney has sold for £4,100 at auction.

The three inch by three inch drawing dates back to 1957 when, a 20-year-old Hockney went on holiday to Suffolk with two fellow artists.

They befriended a local girl, 17-year-old Kathleen Wright, who worked in a tea shop. When she learnt they were artists she said she should get their autographs in case they became famous.

She cycled home to get her autograph book and all three signed it. Hockney also drew a self-caricature.

Hockney went on to become one of this country's most iconic artists with his work selling for millions of pounds.

Miss Wright kept the sketch for more than 40 years before finally deciding to sell it and yesterday it went on sale again.

Graham Paddison of Brown & Co auctioneers in Brigg, Lincolnshire, who handled the auction, said: "It's a charming story. In effect, all it really is is a leaf from an autograph book. But David Hockney is a hugely topical and collectable artist."

The pre-sale estimate for the sketch was £4,000 to £5,000 and bidders were mainly private collectors. The successful bidder was unnamed.