"On Sunday next week, when we put him in his grave, all the rituals will be conducted by the Royal House," Xhosa traditional leader Nokuzola Mndende told AFP.
"It will be a traditional ritual and the government should take a back seat and not interfere," she added.
Mandela was born into the Thembu royal family, the leaders of a Xhosa-speaking people.
"An ox will be slaughtered to accompany him. It is only the Mandela clan which will conduct the rituals on burial day to prepare him for a safe journey."
"If government intervenes, the ancestors will not accept and welcome him, and this will have a detrimental effect on the family members left behind as his spirit will come back to haunt them."
Mandela is due to be buried at his childhood home of Qunu on Sunday, part of a week-long celebration of his life.
In contrast to a stadium memorial in Soweto and a laying in state in Pretoria, Mandela's hometown burial will be more traditional, a mixture of Christian and traditional Xhosa rites.
