Johannesburg (AFP) - Zimbabwe's first lady Grace Mugabe has claimed diplomatic immunity after being accused of assaulting a 20-year-old model, South African police said Wednesday, in an incident that could test cross-border relations.
The 52-year-old wife of President Robert Mugabe is accused of attacking Gabriella Engels on Sunday evening at a Johannesburg hotel where the first lady's two sons were staying.
Engels has registered a police case alleging assault with intent to do grievous bodily harm, saying she suffered deep cuts to her forehead and the back of her head.
"The suspect('s) lawyers and her government representatives made verbal representations... that the suspect wished to invoke diplomatic immunity cover," the police ministry said in a statement.
The police said that Grace Mugabe had been expected to report to a police station on Tuesday to give her version of the events and "to obtain a warning statement", but that she failed to show up.
- Public or private trip? -
They added that she would attend at the weekend a summit of the Southern African Development Community (SADC) in Pretoria where her husband and other heads of state will be present.
Her official duties at the summit could bolster her claim to diplomatic immunity, after her trip to see her sons was widely described as private.
Foreign affairs spokesman Clayson Monyela had told AFP on Tuesday that her trip was "a private visit, so government cannot get involved."
Her husband flew out of Harare for South Africa early Wednesday evening for the summit, according to the Zimbabwean public broadcaster ZBC.
The summit of heads of state starts on Saturday.
"We know where the suspect is," South Africa's police spokesman Vishnu Naidoo told AFP earlier Wednesday.
"We are still continuing with the investigations. No warrant of arrest has been issued," he added, after some reports suggested she had hurriedly returned to Harare late Tuesday.
The alleged attack threatens to spark a diplomatic tiff between the two neighbouring countries, which have strong political and economic ties.
Zimbabwean officials have made no comment on the case.
- 'Kept beating me' -
Grace Mugabe allegedly arrived at the Capital 20 West Hotel with bodyguards and accused Engels of partying with her sons Robert and Chatunga, who are both in their 20s and live in Johannesburg.
Pictures on social media appeared to show Engels bleeding from her head after the alleged assault at the hotel in the upmarket business district of Sandton.
Engels said she was attacked with an electrical extension cord.
"She flipped and just kept beating me with the plug. Over and over. I had no idea what was going on. I was surprised... I needed to crawl out of the room before I could run away," she told the News 24 website.
Grace Mugabe is 41 years younger than her 93-year-old husband, and the couple has two sons and a daughter.
She regularly speaks at rallies and is seen as a possible contender to take over from her increasingly frail husband, who has ruled Zimbabwe since independence from Britain in 1980.
The succession battle is expected to pit Vice President Emmerson Mnangagwa against a group called "Generation 40" or "G40" because its members are generally younger, and which reportedly has Grace's backing.
While Grace Mugabe has in the past denied harbouring ambitions to take over from her husband, at other times she has said she would be prepared to serve in any political position.
She has taken on a larger public role in recent years, drumming up support for her husband and heading the women's league of the ruling ZANU-PF party.
In speeches this year the president has often slurred his words, mumbled and paused for lengthy periods.
His reign has been marked by brutal repression of dissent, mass emigration, accusations of vote-rigging and a sharp economic decline.