An astonished family discovered that a painting that decorated their living room for decades was a Van Dyck that could be worth millions

• A family discovered that a painting hanging on the wall of their home could be worth millions.
• The painting was a genuine Anthony van Dyck and had been on their wall for decades.
• The painting, "The Presentation of the Baby Jesus to Saint Barbara," was found in Jaén, Spain.

A family in Spain were shocked to discover that a painting that had hung on the wall of their home for decades was actually by the Flemish Baroque artist Anthony van Dyck and potentially worth millions, Spanish daily newspaper El País reported.

The painting, "The Presentation of the Baby Jesus to Saint Barbara," was found in Jaén, Andalucía, southern Spain. A Madrid art company authenticated it as a van Dyck last year, per the report.

According to the owner's lawyer, the family had "no idea" the painting was an art treasure, a local outlet reported.

The work is believed to have come through Seville, where part of the family had lived, in the 17th Century, before arriving in Jaén. At the time, Seville, which is the capital of the autonomous community of Andalucía, became home to many Flemish families as bankers and merchants flocked to the city, El País reported.

A previous van Dyck paintings to go to auction at Sotheby's sold for £8.3 million, which is about $10 million, according to the auction house's website.

Nevertheless, Consuelo Durán, from the Madrid-based Durán auction house, told El País that it was "very difficult to specify an approximate value of this type of work of art," as "each painting has its own features."

Van Dyck is considered to be "the most important Flemish painter of the 17th century" after the master Peter Paul Rubens, The National Gallery's website says.

Born in Antwerp, in what is now Belgium, van Dyck went on to become a royal court painter for the English monarch Charles I. Many of the painter's most famous portraits came during this period, with "his authoritative and flattering representations" of the king and his relatives setting "a new standard for English portraiture."