"She's not at work," her spokesman Canaan Mdletshe said.
"She is still recovering from last year. She's at home at the moment."
He did not know when kaMagwaza-Msibi was expected back at work, saying it would depend on her doctor.
Mdletshe said the National Freedom Party leader's hospitalisation last year was stress related.
The Newcastle Advertiser reported last year that she was admitted to Mediclinic Newcastle's intensive care unit on November 16, before being transferred to the eThekwini Hospital's ICU.
The Witness newspaper reported at the time that she had suffered a stroke, but this has never been officially confirmed.
Earlier this month, senior NFP officials admitted none of them had spoken to their leader since she took ill in November, but insisted she was doing well.
At the time, NFP secretary general Nhlanhla Khubisa said kaMagwaza-Msibi was recovering from "fatigue and depression".
The SABC reported on Wednesday that the family had barred the party's leaders from visiting kaMagwaza-Msibi. Only Science and Technology Minister Naledi Pandor had access to her.
Source: Sapa