The painting has been the subject of debate for centuries
A portrait thought to have been painted by a pupil of Rembrandt has been proven to have been created by the master himself after a restoration.
Portrait of Pastor Swalmius, painted in 1637, had been the subject of debate by art connoisseurs for centuries.
But curators at Antwerp's Royal Museum of Fine Arts were overjoyed after layers of dark varnish were removed to reveal the Dutch painter's signature.
The portrait will now go on display at the museum from 8 August.
The painting was once owned by the brother of King Louis XIV and was kept in various art collections before being bought by an art handler, who sold it to the museum in 1886 for 200,000 francs.
"There was a very dark varnish on the painting so subtleties within it were not visible anymore and after time people thought it wasn't genuine," museum spokeswoman Veronique van Passel told the BBC News website.
After much debate the painting was kept in storage for decades, but thanks to a Dutch beneficiary, the portrait was restored to reveal its creator and was in "splendid condition" with only one minor cut.
"The signature was exactly the same as the signature and date on Rembrandt's A Polish Nobleman in in the National Gallery of Art in Washington," Ms van Passel said.
The Rembrandt Research Project confirmed the painting's authenticity after tests showed it was made from the same piece of linen as two other genuine Rembrandts - one on display in Frankfurt and the other in St Petersburg.
It also pointed to features of the collar, beard and wrinkle of the eyes which were characteristic of Rembrandt's style.