A new book by a former South African military doctor that documents Nelson Mandela's medical treatments before his 2013 death violates doctor-patient confidentiality, according to some relatives of the anti-apartheid leader and Nobel laureate.

But the retired doctor, Vejay Ramlakan, said in an interview this weekend on the eNCA news channel that the Mandela family had requested that the book be written. While Ramlakan declined to say which family members had given permission for the book, his remarks could indicate continuing rifts in a family whose members have feuded over the years on issues such as inheritance.

The book, "Mandela's Last Years," covers Mandela's health while he was imprisoned during white minority rule, during his tenure as South Africa's first black president and in retirement. It also focuses on the dramatic final months of Mandela's life, when he was suffering a lung infection and other ailments before dying at age 95.

"It documents the complex medical decisions; disputes between family members and staff; military, political, financial and security demands; constant scrutiny from the press; and the wishes of Mandela himself, all of which contributed to what he and those closest to him would experience in his final days," according to Penguin Random House, the publisher.

Mandela's widow, Graca Machel, said she is considering legal action and will consult with the executors of Mandela's will, South African media reported.

"We are deeply disappointed that the doctor appears to have compromised himself and the man whom he had the privilege to serve," Nkosi Mandela, a grandson of the anti-apartheid leader, said in a statement. He said the book might contain ethical violations.

In the eNCA interview, Ramlakan said he had permission to write the book and that "all parties who needed to be consulted were consulted."

Winnie Madikizela-Mandela, Mandela's ex-wife and a prominent figure in the anti-apartheid movement, was with her former husband when he died, according to Ramlakan, a former surgeon general of South Africa who headed Mandela's medical team.

"She's the one who was there when he passed on," he said. "I think Mrs. Machel was in the house or busy with other issues. But I have no idea because I was focusing on my patient."

AP