Camilo Guevara March, the 60-year old son of Argentine-born revolutionary leader Ernesto "Che" Guevara, has died.
Cuban officials said he died of a heart attack caused by blood clots in his lungs.
He opposed the use of his father's image - made famous by an Alberto Korda photograph - for marketing purposes.
Camilo is one of four children Che Guevara had with his second wife, Aleida March.
While his older sister Aleida took on the role as spokeswoman for the family, Camilo led the Centre of Che Guevara Studies in the Cuban capital, Havana.
The centre, where Che Guevara's personal archives are stored, promotes the revolutionary leader's "life, work and thought".
Cuban officials said Camilo Guevara died while on a visit to the Venezuelan capital, Caracas.
Born in Argentina, Che Guevara arguably became the most famous face of the Cuban revolution after joining brothers Fidel and Raúl Castro in their successful fight to overthrow the government of Fulgencio Batista.
Camilo Guevara was the second of four children born to Che Guevara and his fellow rebel, Aleida March.
He was five years old when his father was shot dead in Bolivia, where he had travelled to set up a guerrilla group.
He studied law but spent much of his life looking after the documents and memorabilia left behind by his father.
Unlike some of Fidel Castro's close relatives who became vocal critics of the aftermath of the Cuban revolution, such as his sister Juanita Castro and his daughter Alina Fernández, Camilo Guevara remained loyal to the Castro brothers.
Fond of photography, he could often be seen clutching a Leica camera in one hand and a cigar in the other.
He is survived by his 85-year-old mother Aleida, his 61-year-old sister - also called Aleida - who works as a paediatrician, his younger sister Celia, who is a vet, and his younger brother Ernesto, who runs motorcycle tours of the Communist-run island.
He also leaves behind a daughter from his marriage to the late Cuban singer Suylén Milanés and two daughters from his subsequent marriage to Venezuelan Rosa Aliso.