Zindzi Mandela, the daughter of South African anti-apartheid leaders Nelson and Winnie Mandela, has died at the age of 59.
State television South African Broadcasting Corporation reported that Ms Mandela died in hospital in Johannesburg early on Monday morning.
The cause of her death has not been announced.
She had been South Africa’s ambassador to Denmark since 2015.
She read his letter rejecting the offer at a packed public meeting which was broadcast around the world.
Last year, Ms Mandela sparked controversy by calling for the return of white-owned land to South Africa’s dispossessed black majority.
“Dear Apartheid Apologists, your time is over. You will not rule again. We do not fear you. Finally #TheLandIsOurs,” she tweeted in June last year.
South Africa’s foreign affairs minister, Naledi Pandor, expressed shock at Ms Mandela’s death, describing her as a heroine.
“Zindzi will not only be remembered as a daughter of our struggle heroes, Tata Nelson and Mama Winnie Mandela, but as a struggle heroine in her own right. She served South Africa well,” said Ms Pandor.
Ms Mandela is survived by her husband and four children.