Nelson Mandela has left hospital and has gone to his Johannesburg home, where he is continuing to receive intensive care, the South African presidency says on its website.

The announcement came a day after officials denied reports that the 95-year-old had already been discharged.

The statement says Mr Mandela condition remains critical and at time unstable.

South Africa's first democratically elected president has been in hospital since June with a lung infection.

"His team of doctors are convinced that he will receive the same level of intensive care at his Houghton home that he received in Pretoria [hospital]," the presidency statement says.

It says his home has been "reconfigured to allow him to receive intensive care there" and he will be treated by the same health care personnel as in hospital.