MADRID, Spain — Ailing Cuban leader Fidel Castro has had at least three failed operations and complications from an intestinal infection and faces "a very grave prognosis," a Spanish newspaper reported today.

A Cuban diplomat in Madrid said the reports were lies and declined to comment.

"It's another lie and we are not going to talk about it. If anyone has to talk about Castro's illness it's Havana," the diplomat said, speaking on condition of anonymity because of official policy.

The newspaper El Pais cited two unnamed sources from the Gregorio Maranon hospital in the Spanish capital of Madrid. The facility employs surgeon Jose Luis Garcia Sabrido, who flew to Cuba in December to treat the 80-year-old Castro.

In a report published on its Web site, El Pais said: "A grave infection in the large intestine, at least three failed operations and various complications have left the Cuban dictator, Fidel Castro, laid up with a very grave prognosis."

Cuba has released little information on Castro's condition since he temporarily ceded power in July to his brother, Defense Minister Raul Castro, until he could recover from emergency intestinal surgery, prompting much speculation and rumor in the country and around the world.

Some U.S. doctors believe Castro is suffering from diverticular disease, which can cause bleeding in the lower intestine, especially in people over 60. In severe cases, emergency surgery may be required.

El Pais reported that Castro had suffered a bout of the disease.

"In the summer, the Cuban leader bled abundantly in the intestine," El Pais reported. "This adversity led him to the operating table, according to the medical sources. His condition, moreover, was aggravated because the infection spread and caused peritonitis, the inflammation of the membrane that covers the digestive organs."

A second operation also failed, the paper said. Castro was then hit with inflammation of the bile duct, an illness which has a 80 percent mortality rate, el Pais said. A prothesis made in South Korea was implanted and failed and later was replaced with one made in Spain.

A statement attributed to Castro was released on New Year's Eve saying his recovery was "far from being a lost battle."