Nkosazana Dlamini Zuma Photo: Antoine de Ras/Independent Media

Johannesburg - Former African Union Commission chairperson, Nkosazana Dlamini-Zuma on Thursday said Zimbabwe's First Lady Grace Mugabe, who is accused of beating up a young South African model, must face the law.

Answering questions at her book launch, Dlamini-Zuma said women were capable leaders and the bad behaviour of one woman should not be allowed to taint all women. 

Mugabe, 52, allegedly used an electric extension cord with a plug at one end to whip 20-year-old Gabriella Engels and her friend after she found them at the hotel where her sons, Robert Jnr and Chatunga Bellarmine, were staying since being evicted from their R74,000-a-month Sandton apartment for brawling.

The attack, which left Engels with a gash on the face and bruises to the body, took place on Sunday. 

Mugabe, who has been previously accused of beating up reporters in Asia, remains at the centre of a diplomatic riddle as questions over her immunity from prosecution persist. 

"Whether one beats another ... it is wrong and the law must take its course ... but women are capable ... they can not be judged on that," said Dlamini-Zuma, who is in the running to lead the African National Congress (ANC) in December when the party will elect a fresh leadership.

"We are sexist, we are in a patriarchal society and we must get out of it."

Dismissing suggestions that Grace Mugabe's alleged bad behaviour was a blight on women aspiring to lead, the former AU Commission chair said "women are human beings ... like anybody else some make mistakes ... just like men do."

President Robert Mugabe, 93, arrived in South Africa late Wednesday for this week's 37th Southern African Development Community (SADC) summit in Pretoria. Reports said the nonagenarian arrived earlier than initially planed in order to deal with his wife's woes.  

The South African Police Service said the Zimbabwean First Lady had failed to honour agreements to hand herself over leading to speculations that she had slipped out of the country, but it has since been established that she remains holed up at a secret location.

Zimbabwean authorities have told their South African counterparts that Mugabe enjoys diplomatic immunity because she had specific duties at the SADC summit. The matter is with the Department of International Relations and Cooperation in South Africa.

* Titled the “African Union Commission Under the Leadership of Dr. Nkosazana Dlamini-Zuma”, the book gives a glimpse of the her work between 15 October 2012 and 14 March 2017, when she handed over the reins to Chadian diplomat, Moussa Faki Mahamat.