Winnie Madikizela-Mandela

The family said in a statement that she passed away at the Netcare Milpark Hospital in Johannesburg, South Africa, after a long illness, for which she had been in and out of hospital since the start of the year.

"Mrs. Madikizela-Mandela was one of the greatest icons of the struggle against apartheid," the statement said. "She fought valiantly against the apartheid state and sacrificed her life for the freedom of the country."

Her death came as a shock. "None of us had predicted this," a family spokesman told CNN.

Members of the Mandela family were in the cramped courtroom where Mbuso Mandela, 24, appeared. He has been in police custody since his arrest on Saturday.

According to South African law, due to the seriousness of the charge, his defense attorneys will have to present evidence to support his release on bail.

The rape allegedly took place in a toilet at a restaurant in Greenside, a Johannesburg suburb, on Aug. 7, police said.