South African police are still negotiating with the legal team of Zimbabwe's first lady to get her to hand herself in and face court over allegations she attacked a model.

Gabriella Engels has accused Grace Mugabe of assaulting her while she was visiting the first lady's sons in a hotel room in an upmarket suburb of Johannesburg.

The 20-year-old claims the first lady's bodyguards stood and watched as Mrs Mugabe, 52, hit her with an extension cord.

She posted a picture on social media showing a gash in her forehead, which she claims is a result of the alleged encounter.

"I had no clue who this woman was when she started beating me," Ms Engels told local radio station 702.


I have to more injuries at the back of my head pic.twitter.com/fz3olUz9tN — Gah-bee (@DaNamesGaby) August 14, 2017

Police minister Fikile Mbalula had said earlier that Mrs Mugabe had handed herself in to police and would appear in court.

But a senior police source told the Reuters news agency: "The negotiations for her to hand herself in are still going on. We are at a point where we cannot effect an arrest yet."

A Zimbabwean intelligence source told Reuters that Mrs Mugabe was travelling on a normal passport.

South African media reports say diplomatic immunity will not apply in the case because Mrs Mugabe is not a part of Zimbabwe's government or a government official.