A Pablo Picasso portrait of his teenage mistress has sold for £25.2 million at auction.

La Lecture, bought anonymously, fetched more than double its low estimate of £12 million at Sotheby’s Impressionist and Modern Art sale in London.

Painted in 1932, the painting depicts Picasso’s 17-year-old lover Marie-Therese Walter asleep in an armchair.

Walter was also the inspiration for Picasso’s Nude, Green Leaves and Bust, which sold for a world record for any art at any auction of £69.8 million, in New York in May last year.

The couple’s relationship was a well-guarded secret for many years due to the fact that Picasso was married to Russian-Ukrainian dancer Olga Khokhlova and because of Walter’s young age.

Helena Newman, chairman of Sotheby’s Impressionist & Modern Art Europe, said: “We were thrilled with the price achieved for Picasso’s La Lecture – an exceptional work from one of the artist’s most celebrated periods.”

The painting attracted strong pre-sale interest from across the globe, with seven bidders driving the price to a final £25,241,250.

Le Maitre D’Ecole by Rene Magritte sold for £2.2 million in the auction, breaking the previous record for his work on paper, £1.2 million, which was the expected sale.

Other notable works which went under the hammer included Claude Monet’s Argenteuil, Fin D’Apres-Midi and Alberto Giacometti’s Grande Buste de Diego avec Bras.