The work is said to be by Swiss sculptor Alberto Giacometti and is featured in tonight’s series finale of the BBC’s Fake Or Fortune?
Art expert Philip Mould and presenter Fiona Bruce set off to find the truth after owner Claire Clark-Hall and her daughter Henrietta Plunkett brought them the sculpture, known as The Gazing Head.
Clark-Hall explained: “It was acquired by my grandmother. She was studying in Paris in the 1930s and she used to sit for the artist [Andre] Derain. She was also friends with the mistress of Giacometti.
“She always liked his work and went back to Paris with her husband to buy one. She wanted to get the bronze [version] but couldn’t stretch to it.”
The stark, white rectangle of plaster has been in the family ever since, but met with a terrible mishap.
“The cat knocked it off the mantelpiece,” said Clark-Hall, “and it smashed into a million pieces.
“My grandfather then used some Polyfilla and covered it in paint. It’s always been at home, but we have no other evidence that it’s a Giacometti.”
As Bruce and Mould work to find the artwork’s provenance they go to a London gallery to examine other pieces by the sculptor, who died in 1966. Two similar Giacomettis are held in a New York museum. They are believed to be from the same plaster mould.
Philip Mould said: “This one is not as desirable as bronzes which are worth millions. This is in plaster but we could be talking hundreds of thousands of pounds.”
Twentieth-century works are hot property. Giacometti’s Man Pointing sold for $141million (£109million) at a New York auction in 2015, making it the most expensive sculpture ever sold.
The quest to discover the history behind the plaster head leads the team to the bohemian world of Thirties Paris.
They also use a CT scan, usually used in hospitals, to examine the damage from its mantelpiece fall, in the hope it will yield further clues. Mould says proving the authenticity of sculptures is “notoriously difficult”.
Works are often produced in batches and he goes to Germany to find out how police broke up a forgery ring that churned out thousands of fakes. The episode closes with the final verdict of fake or fortune, resting with the Giacometti Committee in Paris.
Fake Or Fortune? BBC One, 8pm.