In a controversial move, the Prado has withheld a widely acclaimed Francisco de Goya work from an upcoming exhibition, citing doubts about the painting's attribution, the Independent reports. The painting, El Coloso (The Colossus) (c. 1808), which is owned by the museum, depicts a giant naked man rising above a dark landscape with his eyes shut and fists clenched, while people and animals flee.

"Our knowledge of Goya's work has advanced greatly in recent years, and doubts over the attribution of El Coloso are widely accepted by the museum's scientific team," said Prado director Miguel Zugaza. Zugaza has promised that the evidence supporting the decision will be made public, but has not indicated when.

The work has long been identified as the painting cataloged by Goya's son in 1812 under the entry "Number 18 Un Gigante (A Giant)," but Goya specialist Juliet Wilson-Barreau first raised questions about its provenance, as well as that of the Goya painting La Lechera de Burdeos (The Milkmaid of Bordeaux), in Spain's art review El Periodico in 2001. Citing a lack of energy and bad display, Wilson-Barreau was backed by Manuel Mena, the Prado's senior Goya expert and curator of the current exhibition, but dismissed vehemently by the then-director of the museum. Nigel Glendinning, a professor of art history at London University, responded to Wilson-Barreau's article with an academic study defending the painting. The issue then dropped from public eye until now.

The exhibition "Goya in Times of War" opens at the Prado on April 15 to mark the 200th anniversary of Napoleon's invasion of Spain, with 200 works by the artist, many of which have never been seen in public.