THE HAGUE — Amsterdam’s Van Gogh Museum on Monday unveiled a newly discovered painting by the Dutch master, a find labelled “a once-in-a lifetime experience.”

“Sunset at Montmajour,” a large oil landscape, was unveiled to applause by the museum’s director Axel Rueger as a “unique experience that has not happened in the history of the Van Gogh Museum.”

Depicting a landscape of oaks, the painting was brought to the museum from a private collection, where researchers set to work and authenticated it based on comparisons with Van Gogh’s techniques and a letter he wrote on July 4 1888, in which he described the painting.

It had been lying for years in the attic of a Norwegian collector who thought the painting was a fraud, after buying it in 1908.

“This discovery is more or less a once in a lifetime experience,” said researcher Louis van Tilborgh, who helped with its authentication.

“There is no doubt that it is a Van Gogh,” he added.

The Van Gogh Museum reopened its doors to the public in early May with a stunning new display of the some of the Dutch master’s greatest works, completing a trio of renovations of the city’s most famous museums.

It is located on Amsterdam’s historic Museumplein where many other Dutch art treasures like Rembrandt’s “Night Watch” can also be found at the recently reopened Rijksmuseum.

The museum features 200 works, 140 by the Dutch master himself and the rest by contemporary painters.

They include other iconic works such as “The bedroom”, the “Irises”, “The Potato Eaters” and the ominous “Wheatfield with crows.”

The newly unveiled Van Gogh will go on display on September 24 with other works by the Dutch master.

With its reopening, the museum expects to attract some 1.2 million visitors over the next year and is one of the world’s 25 most popular museums, according to the City of Amsterdam.

The Van Gogh Museum was the last of Amsterdam’s three major museums to reopen its doors after extensive refurbishments, underlining the Dutch capital’s status as a top art destination.