Retired CIA officer says Cuban leader ordered intelligence officer to listen for news from Texas on morning of shooting

It is one of history's most enduring mysteries and has kept conspiracy theorists buzzing for half a century: did Fidel Castro have a hand in the assassination of President John F Kennedy? Officially, the Cuban dictator was cleared of involvement in the shooting of his fiercest adversary. The inquiry into the murder concluded that Lee Harvey Oswald, a communist sympathiser, acted alone.

Now a retired CIA officer claims to have proof that Castro knew the murder was about to happen – an allegation certain to refuel speculation before next year's 50th anniversary of a pivotal moment of the 20th century.

Brian Latell, who studied Cuban affairs as a CIA analyst in the 1960s and became the agency's chief intelligence officer for Latin America, says in a book that he is certain Castro knew.

On the morning of 22 November 1963, the day Kennedy was killed in Dallas, Castro ordered a senior intelligence officer in Havana to stop listening for non-specific CIA radio communications and to concentrate on "any little detail, any small detail from Texas", Latell claims in his book Castro's Secrets – the CIA and Cuba's Intelligence Machine, due to be published next month.

Four hours later came news that Kennedy was dead. Latell claims Castro was aware that Oswald, who had been denied a visa to visit Cuba at the embassy in Mexico City, told staff there he was going to murder Kennedy to prove his communist allegiance. "Fidel knew of Oswald's intentions and did nothing to deter the act," Latell writes.

In an interview published on Sunday in the Miami Herald, Latell, now a senior lecturer on Cuba at the University of Miami, said he discovered the information in interviews with Cuban former intelligence officers, backed up by declassified US government documents.

"I don't say Fidel Castro ordered the assassination, I don't say Oswald was under his control. He might have been, but I don't argue that, because I was unable to find any evidence for that," he said.

"[But] everything I write is backed up by documents and on-the-record sources … Did Fidel want Kennedy dead? Yes. He feared Kennedy. And he knew Kennedy was gunning for him. In Fidel's mind, he was probably acting in self-defence."

Latell's book, billed as the first in-depth study of Castro's intelligence operations in the years after the Marxist revolutionary seized power in a coup in 1959, says there is strong supporting evidence. It claims that CIA wiretaps of Cuban intelligence agents after the assassination revealed they had a surprising knowledge of Oswald's background when only scant details had been reported by the media.

But it is Latell's interview with the Cuban former intelligence officer, Fiorentino Aspillaga Lombard, who was in charge of Castro's listeners at his Havana compound, that will raise eyebrows.

Aspillaga, who defected to the US in 1987, told Latell that he told the CIA at his debriefing that Castro personally issued the order to listen for anything about Texas. That information was never revealed publicly and he never repeated it until he was interviewed for the book.

After his defection, Aspillaga lifted the lid on Castro's lavish lifestyle, giving details of his luxury yachts, lavish properties in each of Cuba's provinces and a secret Swiss bank account containing millions of dollars.

The claim that Castro was aware of Oswald's promise to Cuban embassy officials to murder Kennedy comes from several sources, including a former FBI informant and "superspy" Jack Childs, who infiltrated the dictator's inner circle.

Childs said Castro told him Oswald "stormed into the embassy, demanded the visa, and when it was refused to him headed out saying, 'I'm going to kill Kennedy for this'."

Castro claimed in public that Oswald's visit to the embassy was "a minor matter" that had not been noticed by senior officials in Havana.

Investigations by the US security agencies and the Warren commission inquiry into Kennedy's assassination looked at Castro's possible involvement but concluded that Oswald was a lone gunman acting independently.

Among other issues discussed in Latell's book are the CIA's attempts to assassinate Castro using a variety of methods, including exploding cigars and poison pens. He says the efforts were called off after Kennedy died.