Rumours are swirling Fidel Castro has suffered a stroke and is close to death.
Venezuelan Dr Jose Marquina told El Nuevo Herald the 86-year-old had suffered a cerebral haemorrhage.
Dr Marquina said: “He suffered an embolic stroke and recognises absolutely no one.”
The Cuban government has made no official statement on Castro's health - which is a matter of national security - and the ageing revolutionary's family have denied reports of his poor health.
Dr Marquina's comments are uncorroborated and AP points out he is the same physician who made predictions in April that cancer-stricken Venezuelan President Hugo Chavez was "in his last days" and would be dead by November.
Chavez says he has beaten the illness and continues to appear in public.
Castro was last seen in public in March – during a visit from Pope Benedict XVI to Cuba.
Cuban President Fidel Castro addressing hundreds of thousands of people at the Revolution Square in Havana 01 May, 2000. A top Cuban official would not confirm or deny 30 April, 2007 that President Fidel Castro might attend annual May Day events in Cuba, in what would be the convalescing leader's first public appearance in nine months since he underwent major surgery nine months ago. AFP PHOTO/ADALBERTO ROQUE (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)
Photo dated February 2002 of Castro's elder son, nuclear physicist Fidel Castro Diaz-Balart (R), during the Havana Book Fair opening. Cuban media have interviewed recently some of Castro's eight sons, who are still unknown by most Cubans, without mentioning their father. AFP PHOTO/Adalberto ROQUE (NOTE: Goes with article 'Fidel's intimacy unveiled', by Carlos Diaz.) (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)
This 01 May 2002 photo shows Cuban President Fidel Castro waving a Cuban flag during a May Day rally in Havana. The Spanish newspaper El Pais is reporting 16 January 2007 that the Cuban leader is in 'very grave' condition, following three failed operations and complications from an intestinal infection. The newspaper cites two unnamed sources from the Gregorio Maranon hospital in the Spanish capital of Madrid. AFP PHOTO/FILES/Adalberto ROQUE (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)
A file photo taken 26 May 2003 shows Cuban President Fidel Castro talking to reporters, after a meeting with newly-installed Argentine President Nestor Kirchner at the government house in Buenos Aires. Castro 30 January 2004 accused US President George W. Bush of planning to have him assassinated to overthrow Cuba's communist government. Castro also warned he was ready to 'go down fighting' if the United States should try to invade Cuba at any time. AFP PHOTO ALI BURAFI (Photo credit should read ALI BURAFI/AFP/Getty Images)
This 20 July 2006 photo shows Cuban President Fidel Castro waving upon his arrival at airport in Cordoba, Argentina to participate in the Mercosur's presidential summit. The Spanish newspaper El Pais is reporting 16 January 2007 that the Cuban leader is in 'very grave' condition, following three failed operations and complications from an intestinal infection. The newspaper cites two unnamed sources from the Gregorio Maranon hospital in the Spanish capital of Madrid. AFP PHOTO/FILES/Juan MABROMATA (Photo credit should read JUAN MABROMATA/AFP/Getty Images)
Cuban President Fidel Castro attends a ceremony outside of the U.S. Interests Section in Havana, Cuba, Friday, Feb 24,2006. Castro saluted solemnly on Friday as cannon fire reverberated across Havana Bay and a forest of huge Cuban flags were raised outside the American mission to remember Cuba's 1895 War of Independence.(AP Photo/ Javier Galeano)
This 12 February 2005 file photo shows Cuban President Fidel Castro meditating during the VII International Globalization Meeting in Havana. The Spanish newspaper El Pais is reporting 16 January 2007 that the Cuban leader is in 'very grave' condition, following three failed operations and complications from an intestinal infection. The newspaper cites two unnamed sources from the Gregorio Maranon hospital in the Spanish capital of Madrid. AFP PHOTO/FILES/Adalberto ROQUE (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)
Picture taken July 1953 shows guerrilla leader Fidel Castro (C) with a group of comrades in Los Palos, Havana province, during the preparation of the attack on the Moncada Garrison. Standing on the left: Antonio (Nico) Lopez and Abel Santamaria, on the right: Jose Luis Tasende and Ernesto Tizol. Cuba will celebrate, 26 July 2003, the 50th anniversary of the Moncada assault which gave way to the revolution led by Castro. AFP PHOTO/PRENSA LATINA (Photo credit should read PRENSA LATINA/AFP/Getty Images)
This picture from December 15, 1986, shows former Cuban President Fidel Castro (C), Nobel Literature Prize Gabriel Garcia Marquez (L) and movie director Fernando Birri (R) during the inauguration of the International School of Cinema in San Antonio de los Banos, Havana province. AFP PHOTO/Adalberto ROQUE (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)
Cuban leader Fidel Castro is seen looking pensive in his office in Havana's Presidential Palace, 1985. (AP Photo/Charles Tasnadi)
Fidel Castro exhales cigar smoke during a March 1985 interview at his presidential palace in Havana. Castro, a Havana attorney who fought for the poor, overthrew dictator Fulgencio Batista's government. (AP Photo/ Charles Tasnadi)
Fidel Castro, former law student now rebel leader in Cuba. Picture date: Feb. 26, 1957. (AP Photo)
Cuba's revolutionary hero Fidel Castro, right, signs the Instrument of Office to become Prime Minister of Cuba, at a ceremony in Havana, Feb. 16, 1959. Cuban President Manuel Urrutia, left, waits to place his signature on the document. (AP Photo)
Fidel Castro, Cuba's new revolutionary leader, speaks to a crowd during his triumphant march to Havana, after the fall of the Batista regime, Feb. 6, 1959. (AP Photo)
Cuban Prime Minister Fidel Castro, speaking in Havana, April 16, 1961, blames President John F. Kennedy and U.S. Government for the dawn air raids on three Cuban cities the day before. Speaking at a military funeral and demonstration to honor seven victims of the raid on Havana, Castro termed the attacks Cuba's Pearl Harbor. He disputed reports that pilots of the bombing aircraft had defected from his own air forces. (AP photo)
Cuban revolutionary leader Fidel Castro spekas to supporters Jan. 8, 1959 at the Batista military base "Columbia," now known as Ciudad Libertad. On Jan. 1, 1959, dictator President Fulgencio Batista fled the country and Castro's rebels took control. (AP Photo)
Cuban Prime Minister Fidel Castro speaks on the eve of the military trial of more than a hundred insurgents captured in the mountains on Wednesday Oct. 10, 1960 in Havana. He warns "He who lives by the sword shall die by the sword" to those who attacked his regime. (AP Photo)
Cuban Prime Minister Fidel Castro responds to a question from American NBC reporter Barbara Walters during a news conference granted to members of the U.S. press covering Senator George McGovern's trip to Cuba, in Havana, May 7, 1975. (AP Photo)
Ernest Hemingway and Cuban Prime Minister Fidel Castro exchange pleasantries at seaside after Castro won the individual championship in the annual Hemingway Anglers Tournament on May 15, 1960. Castro caught five fish weighing 286 pounds to take the crown. Hemingway had a bad day failing to land any. (AP Photo/str)
Cuban Prime Minister Fidel Castro, visiting the U.S., takes a good sized bite of hot dog during a trip to New York's Bronx Zoo April 24, 1959. Hot dogs are not unknown to Cuba, but are not nearly as common as they are in the U.S. (AP Photo/John Lindsay)
Bare-chested Fidel Castro, Premier of Cuba, takes up a paddle against U.S. students in table tennis contest at Varadaro, Cuba. Picture date: August 30, 1963. Castro challenged the students, who had gone to Cuba in defiance of a U.S. State Department ban, and said that if he lost to a student, the student would become Cuban Premier and Castro would become a student. The validity of the challenge was untested because Castro defeated all competition. (AP Photo/John F. Saltor)
Raul Castro, left, younger brother to Cuban rebel leader Fidel, has his arm around second-in-command, Ernesto "Che" Guevara, Argentine national, in their Sierra de Cristal Mountain stronghold south of Havana, Cuba, during the Cuban revolution in June 1958.
Cuba's Prime Minister Fidel Castro and Soviet Premier Nikita Khrushchev, embrace one another at the UN General Assembly, at the United Nations Building, in New York, NY, Sept. 20, 1960. (AP Photo)
Cuban Prime Minister Fidel Castro with cigar during his meeting with U.S. senators Javits and Pell during their meeting in Havana, Cuba, September 29, 1974. (AP Photo/Charles Tasnadi)