The latest photo of Fidel Castro emerged earlier in February
Venezuelan President Hugo Chavez says former Cuban leader Fidel Castro, not seen in public for nearly three years, has been for a walk in Havana.
Mr Chavez, who visited Cuba a week ago, said in comments carried by Venezuelan state TV that Mr Castro had seemed in "very, very good" shape.
Media in Cuba have neither reported nor confirmed Mr Chavez's tale.
Mr Castro, 82, has not made a public appearance since undergoing gastric surgery in July 2006.
He handed over presidential duties in 2006, and formally announced his retirement as president in February 2008, allowing his younger brother Raul to take over as head of state.
The BBC's Michael Voss, in Havana, says it is not unusual for updates on Fidel Castro's health to come from abroad.
The last photos of him to emerge were released in Chile, following a visit to Cuba by Chilean President Michelle Bachelet, our correspondent says.
In those images the former Cuban leader looked stronger than before and appeared to have gained some weight, he adds.
Speaking on Friday in Caracas, the Venezuelan capital, Mr Chavez said: "Fidel surprised us all.
"He went for a walk. Fidel went out and they saw him... Fidel walking through Havana, through the streets. A miracle. The people were crying.
"Of course he planned it all so there wouldn't be any record of it or anything," Mr Chavez added. "There's a photo that I've seen, and in that sense I feel humbly privileged."
There was no mention of when the walk took place.
The Venezuelan leader also said Fidel Castro this week sent him a letter in which he said he had walked "far", aiming to visit trees he planted 40 years ago in farm experiments in the early days of Cuba's revolution.
Mr Chavez said he had met Fidel Castro for three hours on 20 February and for four hours a day later.
The two men discussed the global economic crisis and the new administration of US President Barack Obama, the Venezuelan government said.
Rumours about the extent of Mr Castro's health problems were fuelled in January, when he did not appear in public for celebrations marking the 50th anniversary of Cuba's revolution.
The non-appearance fuelled suspicions that his health had deteriorated badly.