Italian police are investigating three organisers of a Modigliani exhibition after all but one of the paintings were shown to be fake.

The exhibition opened to great fanfare in Genoa last March, but closed in July after experts raised suspicions that the works were forgeries.

Art historians have now concluded that 20 of the paintings are indeed fakes.

Amedeo Modigliani’s work often fetches huge sums, but experts say he’s one of the most copied artists in the world.

The fakes from the Genoa exhibition, which was held at the city’s Ducal Palace, will now be destroyed, in accordance with Italian law.

The palace, which was forced to close the show three months early, is itself seeking damages from the private organisers of the exhibition.

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Modigliani fakes have caused scandals in the past. In 1984, three marble heads fished from a canal in Livorno in Italy were hailed as lost works by the artist. They were in fact sculpted by three local students as a prank.

Speaking to Italian daily newspaper Corriere della Sera, one of the exhibit’s two curators, Rudy Chiappini, defended his role, arguing that he had taken the works’ authenticity on good faith.

“I gathered the information and the documentation that was supplied to me for every canvas,” Mr Chiappini said.

“If there have been irregularities, you need to go back to the source, to whoever made the first attribution,” he added.

London’s Tate Modern is currently showing a large Modigliani exhibition, billed as the most comprehensive collection of the Italian artist’s work ever held in the UK.

The artist – who died in 1920 – is known for his paintings of elongated, languid figures.