ART specialists have cautiously welcomed the Spanish government’s decision to block the sale of The Crowning of the Thorns, an undated painting thought to be by a follower of the 17th-century Spanish artist José de Ribera, while investigators determine whether it is a misattributed work by the Italian Baroque master Caravaggio (1571-1610).

Ribera studied for a time in Rome, and was an admirer of Caravaggio’s chiaroscuro technique. The painting was set to be in a sale last week in Madrid at the auctioneers Ansorena, but was withdrawn after curators at the Prado Museum said that there was “sufficient stylistic and documentary evidence to suggest that it could be an original Caravaggio”, and the Spanish Culture Ministry placed a temporary export ban on the painting, a statement from the ministry said.

Experts and collectors are wary of “long-lost” works possibly by Caravaggio, as works by the artist have been in high demand since only the last century, and, as a result, many “Caravaggio” works of disputed provenance have turned up in contemporary high-tariff sales. A Caravaggio specialist who preferred to remain anonymous told The Art Newspaper this week: “Spain doesn’t want to make another export mistake with Caravaggio; they allowed the export of Caravaggio’s Crucifixion of St Andrew, in 1976. Caravaggio’s late style was not fully understood at the time, but the attribution is fully accepted today.”

Ansorena had set a guide price of €1500 for The Crowning of the Thorns; it is thought that, should it be proved to be by Caravaggio, it could be worth more than €50 million to a museum such as the Prado, or €100-150 million to a private buyer.