Art experts have declared that a painting by Vincent van Gogh at the centre of forgery claims is genuine.

Experts at the Van Gogh Museum in Amsterdam have just published research into the authenticity of the Sunflowers painting.

They said there is surviving documentation proving the painting first belonged to Van Gogh's brother Theo.

It was bought by the Yasuda and Marine Insurance Company in 1987 for �25m.

Following the sale, the eminent art expert, Geraldine Norman, declared it was almost certainly not by Van Gogh.

She suggested it had been forged by artist Claude-Emile Emile Schuffenecker while others believed it was in fact the work of Van Gogh's mentor Gauguin.

The National Gallery in London, which sold the painting, has always denied it was a fake.

There was also doubt cast on its authenticity because there was no mention was made of it in his letters or in his family's collection.

But the Van Gogh Museum experts also disputed claims that Schuffenecker forged the whole painting but recognise he restored and made minor additions to the piece.

There were also claims that technical and stylistic inconsistencies existed, but the museum said that examinations of other works by van Gogh revealed similar "errors".

The report, The Tokyo Sunflowers, was written by the museum's curator of paintings, Louis van Tilborgh and head of conservation, Ella Hendriks, in conjunction with the Art Institute of Chicago.

Crucial stage

There are three works in the Sunflowers series, one which usually hangs in London's National Gallery, one at the Van Gogh Museum and the Yusuda version.

The authors have concluded that rather than a mere repetition of an earlier work, the still life represents a crucial stage in Van Gogh's Sunflowers series.

All three are now on display at the Van Gogh Museum, with visitors being able to view the Yasuda Sunflowers for themselves.

Because of the new research, the painting has been redated from January 1889 to November/December 1888, a period when Van Gogh was working in Arles, France, with Gaugin.

The research argues Van Gogh probably made the work in response to Gauguin's now lost still life in yellow, which in turn inspired his friend to paint Portrait of Van Gogh Painting Sunflowers.