Nelson Mandela remained in hospital Saturday, a week after he was admitted for treatment for a lung infection, AFP reports according to the government official.
"Mr Mandela is still in hospital, still comfortable and receiving treatment," said presidential spokesman Mac Maharaj.
Maharaj could not comment on rumours that the 94-year-old could be soon be discharged from Medi-Clinic Heart Hospital, a private facility in the capital Pretoria.
It was not clear when Mandela was moved to the private hospital from the One Military one, the country's top military healthcare facility where government officials initially said Mandela was being treated.
The Heart Hospital bills itself as the first and "only hospital of its kind -- a private, specialised heart hospital -- in South Africa."
The Nobel Peace Prize winner who led the country to democracy in 1994 was flown from his rural home village of Qunu to Pretoria on December 8.
He has a long history of lung problems dating back decades when he contracted tuberculosis while in prison.
He was previously hospitalised for an acute respiratory infection in January 2011, when he was kept for two nights.