Fidel Ángel Castro Díaz-Balart, also known as “Fidelito”, had been treated for depression in the lead, official state newspaper Granma reported .

His father Fidel Castro, a revolutionary turned longserving leader of communist Cuba, died in 2016. Mr Díaz-Balart is believed to be one of several children that Mr Castro fathered with multiple different women.

He was born in 1949 after his mother, Mirta Díaz-Balart, married a young Fidel Castro who was still years away from leading in insurrection that toppled the government of Fulgencio Batista. She was reportedly the only woman that Mr Castro ever married.