But Mandla, 39, ordered the bodies to be exhumed two years ago without the family's approval and they were taken to Mvezo, the village where Mandela was born and where Mandla is chief. The remains are understood to be in simple graves in the compound of a cultural centre and museum built by Mandla in Mvezo, about 30km southwest of Qunu.
This appears to have been an attempt to put pressure on the family to agree to move the elder statesman's eventual grave site to Mvezo, which would then become a lucrative tourist pilgrimage site.
Mandla, whose father was Mandela's second son, was expected to go to court today in Mthatha, the nearest town to Qunu, to oppose the order.
"The way we are handling these matters is contrary to our customs and a deep disappointment to my grandfather and his ancestors," he said. He said he was "sad" his relatives had resorted to court action.
United States President Barack Obama spoke yesterday of how he and his family had been "deeply humbled" to stand in the cell where Mandela was held for 18 years as a South African political prisoner.
Obama and his wife, Michelle, took daughters Sasha and Malia to the museum created from the former prison on Robben Island off the coast of Cape Town for what he said would be "an experience they would never forget".
They were guided by Mandela's close friend and former co-detainee Ahmed Kathrada through the bleak stone quarry where they and the 32 other anti-apartheid activists were forced to work before being taken into Prisoner 46664's tiny cell.
Afterwards, the President and his wife wrote a tribute in the museum visitors' book to Mandela. "On behalf of our family we're deeply humbled to stand where men of such courage faced down injustice and refused to yield," their entry read.
"The world is grateful for the heroes of Robben Island, who remind us that no shackles or cells can match the strength of the human spirit."
Giving the main speech of his African tour at the University of Cape Town later, Obama said he had visited Robben Island before when he was a senator, but his latest visit held far more resonance.
"Mandela's spirit could never be imprisoned because his legacy is here for all to see.
"It's in this auditorium, young people - black, white, Indian, everything in between - living and learning together in a South Africa that is free and at peace. Nelson Mandela shows us that one man's courage can move the world."