In a handout picture released by the National Trust on March 18, 2013 (L-R) Conservation Assistant Cirsty Jones and House Steward Patricia Burtnyk posing with a recently discovered early self portrait of the Dutch artist Rembrandt at the National Trust property of Buckland Abbey near Yelverton in Devon, southwest England. (AFP PHOTO/THE NATIONAL TRUST/STEVEN HAYWOOD)

A painting donated to Britain's National Trust has been identified as a self-portrait of Rembrandt worth about $30 million.

The oil painting was first thought to have been painted by a pupil of the great Dutch painter. However, Rembrandt expert Ernst van de Wetering determined it was actually painted by Rembrandt himself, the heritage conservation charity said Monday.

The estate of the late Lady and Lord Samuel of Wych Cross donated the painting in 2010.

"It's amazing to think we might've had an actual Rembrandt hanging here on the walls at Buckland Abbey for the past couple of years," said Jez McDermott, National Trust property manager at Buckland Abbey.

"We never dared think that it might actually be an original and many of our visitors will have just passed by it, in what is sure to be a real contrast to the attention it is now going to receive."

The painting, dated from 1635, will remain at the museum.