Neither the Mandela family nor the South African government has released details on the final hours of Mandela or given a cause of death.
The account by Holomisa, who says he has known Mandela since he stepped out of prison in 1990, sheds some light on Mandela's condition as his life ebbed away and on the mood and scene inside the Mandela home at that time.
Holomisa said Mandela's wife Graca and his former wife Winnie, one of Mandela's daughters and several of his grand-children were in the house Thursday, where "somberness" prevailed.
Mandela, 95, had been in intensive care at his home in Johannesburg's Houghton neighborhood since he was discharged on Sept. 1 from a hospital where he had spent nearly three months for a recurring lung infection.
Mandela appeared to be sleeping calmly but Holomisa said that it was obvious that he was finally succumbing to illness.
"I've seen people who are on their last hours and I could sense that he is now giving up," said Holomisa, who is the leader of the United Democratic Movement in parliament.
"You could see it is not Madiba anymore," Holomisa added, using Mandela's clan name.
Holomisa said he had previously seen Mandela earlier this year in the hospital.
"This time around he was not on life support," Holomisa said, adding that Mandela was lying on his bed. "I could see that his condition had deteriorated."
Mandela's former wife, Winnie Madikizela-Mandela, said last month that he was unable to speak because of tubes that kept his lungs clear of fluid, according to The Sunday Independent, a South African newspaper.
Holomisa said he spent almost an hour at Mandela's home until around 7 p.m., or about two hours before Mandela died Thursday night.
-AP