A painting discovered by a junk dealer in the basement of an Italian villa six decades ago is actually the work of Pablo Picasso and could sell for millions, according to experts.

The portrait featured the famous artist’s signature in the top left-hand corner. But the owner had no idea who he was.

As a young man, Luigi Lo Rosso used to scour garbage dumps and abandoned homes in Italy for items to sell at his family's shop in Pompeii. In 1962, he was poking around the basement of a Capri villa when he came across a rolled-up canvas.