Zimbabwean First Lady Grace Mugabe. Picture: AP

Johannesburg - Zimbabwean President Robert Mugabe's wife Grace has left South Africa and has been granted diplomatic immunity following her alleged assault on a South African woman, according to media reports on Sunday.

Eyewitness News said it had reliably learnt that Grace Mugabe had left the country. "Sources say the first lady left South Africa in the early hours of Sunday morning along with her husband President Robert Mugabe." 

Robert Mugabe was in South Africa to attend a Southern African Development Community (SADC) summit in Pretoria, but has reportedly left before the summit concludes on Sunday.

"South African authorities had placed a red alert on Grace after she was charged with assaulting 20-year-old model Gabriella Engels last Sunday," EWN reported.

She has applied for diplomatic immunity from the South African government.

The TimesLIVE reported that the Mugabes' departure followed "high-level discussions in South Africa to grant her diplomatic immunity after a hotel rampage that saw Grace assault a woman and hotel staff in Sandton‚ Johannesburg". "It appears that the South African government has indeed granted her immunity," TimesLIVE reported.

The South African government has yet to comment on the matter.