A curator studying Goya's The Colossus at the Prado Museum has expressed doubts that the work, dated to 1808–14, was actually painted by the Spanish master, reports the Guardian.

According to José Luis Díez, the Prado's curator of 19th-century art, who carried out a detailed analysis of the work, the initials in the bottom left-hand corner of the work read "AJ," for Asensio Juli, a Goya assistant who is thought to have collaborated with him on the frescoes in a Madrid church and who signed his own work in this way.

Díez is not the first expert to call the painting's provenance into question: In 2001, the British art historian Juliet Bareau-Wilson claimed that both it and The Milkmaid of Bordeaux had been created by others, a theory supported by Manuela Mena, a Prado conservationist and Goya expert. The Prado denied the claim.

Another British art historian, Nigel Glendinning, firmly believes the work is by Goya. He says that the inscription actually reads "XVIII," which corresponds with a painting called The Giant — an alternative name for The Colossus — in an 1812 inventory of Goya's work.

The Prado says the full findings of Díez's report will be published in the museum's annual report.