The Spanish newspaper El Pais apologized on Thursday for splashing a false photo of Venezuela's cancer-stricken leader Hugo Chavez on its front page, prompting a furious response from Caracas, which vowed to take legal action.

Within minutes of posting the image online as a global exclusive, El Pais said it had discovered from social media that the photo was not of Chavez. It removed it from its website and withdrew its print edition.

Venezuela's government said the publication of the photo - which showed the head of a man lying down with a breathing tube in his mouth - was grotesque, while Argentinian President Cristina Fernandez, a close ally of Chavez, called it vile.