"processed through the legal system", the ministry added.

Discussions were taking place with Mrs Mugabe's lawyers and the Zimbabwean High Commission over the issue, it said.

Appearing before a parliamentary committee earlier, South Africa's acting police chief Lesetja Mothiba said that Mrs Mugabe "must go to court".

media caption Grace Mugabe may face assault charges

She has not commented since police began investigating her over the alleged assault.

South Africa's diplomatic dilemma

Farouk Chothia, BBC Africa

South Africa's government risks a public backlash if it lets Mrs Mugabe go scot-free.

This happened in 2015, when it failed to execute an international arrest warrant for Sudan's President Omar al-Bashir who was wanted by the International Criminal Court.

South Africa's government argued that he qualified for diplomatic immunity, but the country's judges disagreed. The government was then strongly criticisedof assault against Mrs Mugabe after the model, Gabriella Engels, accused her of hitting her over the head with an extension cord.

The alleged assault took place after Mrs Mugabe found her with the first lady's two sons, Robert and Chatunga, in a hotel room in Sandton, a wealthy suburb north of Johannesburg, on Sunday evening.

Mrs Mugabe's sons, who are both in their 20s, live in South Africa.

The first lady was in South Africa to be treated for an ankle injury when the alleged assault took place, Zimbabwean media reported.

Ms Engels released an image of a head injury online.

image copyright Gabriella Engels image caption Gabriella Engels says she was beaten with an extension cord

"When Grace entered I had no idea who she was," she told South African broadcaster News24.

"She