Fake or Fortune presenters Fiona Bruce and Philip Mould, with a painting thought to be an original work by Giorgio de Chirico valued at an estimated £50,000, that has been confirmed as worthless. Picture: Todd-White Art Photography/Ben Fitzpatrick/BBC/PA Wire

Bob Kay bought the depiction of fruit for just £1 in a bric-a-brac shop in Hampshire more than 30 years ago.

It was later thought to be a masterpiece by 20th century artist Giorgio de Chirico, and valued by art dealer and programme co-host Philip Mould at around £50,000.

In Thursday's episode of the BBC One show, presenters Fiona Bruce and Mould discover the truth after submitting the painting to a test in a nuclear laboratory in Florence, Italy.

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A tiny splinter of wood from the painting is tested for radioactive carbon, to date it almost to the year.

Despite the materials being a good match, the Chirico Foundation concluded that the quality and brushstrokes were not consistent with the artist's other work.

Mould said that from ‘the composition, the way the fruit is organised, and the date of the picture - It all indicates someone who knew de Chirico, who worked closely with him, even if it wasn't the master himself.’

The Greek-born painter was credited with influencing the Surrealists, and is the second most-forged Italian artist.