The artwork goes up for auction on June 7 at Brighton and Hove Auctions, based in Warren Road, Woodingdean.
A spokesman for Brighton and Hove Auctions, said: “Recently one of our regular customers walked into our auction room with some items to sell. ‘It’s a Picasso’, he laughed.
“We smiled too and instantly put it down as a copy. No-one brings a long lost Picasso into a provincial auction house on the outskirts of Brighton. No-one brings in a long lost Picasso anywhere and is taken seriously at first glance.”
But closer inspection revealed a signature similar to that of Picasso’s around 1915 - 1918, and a stamp that indicates the painting may have belonged to Picasso’s nephew, Javier Vilato, and the words Roland Penrose Estate. Roland Penrose was a close friend of Picasso and Picasso regularly visited Penrose Chiddingly. The spokesperson said: “Our opinion is that this was a study done by Picasso as part of his body of work resulting in the conception The Bathers. It is a much smaller piece than others in his body of work but signed on the front as well as the reverse. We believe that he probably signed it on the back when he gifted it to his friend Roland Penrose and added the message. The rest is a mystery.”