Havana, Sep 19 - The eldest son of former Cuban president Fidel Castro said Monday that his father is "lucid and working hard", despite having made no public appearance for several months.

"You've seen his message from the other day to (Venezuelan) President (Hugo) Chavez - as always, he's lucid and working hard," Fidel Castro Diaz Balart told EFE.

He was referring to a message his father sent Chavez and which the Venezuelan leader read over the phone Sep 10 during a press conference of his party.

In the message, Fidel Castro said that people who support the Venezuelan president deserve "to enjoy" his victory in the Oct 7 election and hailed Chavez's "iron will".

Fidel Castro, 86, was taken ill in 2006 and delegated power to younger brother Raul Castro, who formally assumed the presidency in 2008.

The elder Castro has retired from public life and since June has not published his famous "Reflections", press articles that he began writing during his convalescence.

In August, a pro-government blog denied stories circulating on the Internet about the state of his health and said that Castro is working on a book with Chavez. (IANS)