Art treasure confirmed as Vermeer

For many years, the work had been thought to be counterfeit

A valuable painting once dismissed as a fake has been confirmed as the work of 17th Century Dutch master Vermeer.

Young Woman Seated at the Virginals, thought to have been painted in about 1670, will now become the first Vermeer to be auctioned in more than 80 years.

It is expected to fetch over £3m at London auction house Sotheby's in July.

Researchers spent more than 10 years studying the painting by the artist - known for more than 30 works including Girl With A Pearl Earring.

The work, measures just 10 by eight inches (25 by 20 cm).

Vermeer's Girl with a Pearl Earring inspired a Hollywood film

The painting was long believed to be a Vermeer - until 1947 when Dutch master forger Han van Meegeren went on trial for selling artworks to the Germans during World War II.

He admitted that he had sold seven fake Vermeers to museums and collectors.

The painting was largely forgotten until it caught the eye of the late Belgian collector and dealer Baron Frederic Rolin in 1960.

In 1993, he showed it to Sotheby's Old Masters specialist Gregory Rubinstein, who suspected it might be the real thing.

Mr Rubinstein said pigments used in the painting matched those that Vermeer used - and which set him apart from his contemporaries.

The dimension of the canvas and its structure matched another Vermeer painting, The Lacemaker, suggesting the canvasses were prepared at the same time.

The last Vermeer to come up for auction was The Little Street in Amsterdam in 1921.