Rupert Maas meets a man who thinks he owns a Hockney Painting.

The discovery of a landscape painting produced by David Hockney when he was visiting Suffolk more than 65 years ago was a "sparkling revelation", a BBC Antiques Roadshow expert said.

The work, a field in pastel colours, was sold by Hockney to a railway signalman near Felixstowe in 1957, and kept by his family.

His grandson took it to the and it was valued at £20-30,000.

Expert Rupert Maas authenticated it and said it was an "extraordinary story".