Fidel Castro health rumor mill continues to churn

The rumor mill about the health of Fidel Castro is churning again, even after state media published a letter attributed to the aging Cuban revolutionary and relatives at home and abroad denied he is on death's door.

Social media sites and some news organizations are reporting allegations by Venezuelan Dr. Jose Rafael Marquina that the 86-year-old Castro has suffered a stroke, is in a vegetative state and has only weeks to live. Some of Marquina's earlier reports on the health of Venezuelan President Hugo Chavez have not panned out.

Castro's health is considered a matter of national security in Cuba and few details are released, prompting regular rounds of speculation.

Castro has not been seen in public since March. Cuba's government had no immediate comment on the new claims.