Brueghel, Boucher, Sorolla... The Prado, in Madrid, investigates the origin of some of his works

Madrid's Prado Museum is investigating the origin of at least 62 works of art from its extensive collection to find out whether they were seized during the Spanish Civil War (1936 to 1939) or Franco's dictatorship.

which ended in 1975, the museum announced. Thursday in a statement.

"

,” the museum explains.

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On Tuesday, the Prado published an initial list of 25 works that had been added to "

”, an organization created by Francisco Franco during this civil war.

In 48 hours, the list has therefore grown, since it contained 62 works on Thursday.

Among these are paintings by François Boucher, the Flemish artist Jan Brueghel the Younger and the Spanish impressionist Joaquín Sorolla, whose photos the museum has published.

The Prado said it has set up a team of investigators led by Arturo Colorado, a cultural heritage and Civil War expert, to determine the provenance of works in the famed museum's collection.

He is due to publish a report in January.

Among the first 25 works identified, 17 paintings were donated to the museum between 1940 and 1942, while six others were initially transferred to the Museo de Arte Moderno in Madrid in 1942-1943 and later acquired by the Prado.