She was 43.

“Zoleka passed away on the evening of Monday, September 25th, surrounded by friends and family,” a statement issued on her Instagram page said.

The Nelson Mandela Foundation also issued a statement to mourn the death of Zoleka Mandela.

"The Nelson Mandela Foundation extends its heartfelt condolences to the Mandela family on the passing of Zoleka Mandela, tragically last night. We mourn the loss of a beloved grandchild of Mum Winnie and Madiba and a friend of the Foundation. When her inspiring memoir When Hope Whispers was published, she graciously signed copies for all our staff and ran a leadership session for the staff around the book," read the statement issued by the Foundation.

The foundation said Zoleka was a 'tireless activist' for healthcare and justice.

"Her work in raising awareness about cancer prevention and her unwavering commitment to breaking down the stigma surrounding the disease will continue to inspire us all," the statement said.