Grace Mugabe 'banned from leaving South Africa' as pressure mounts over assault allegations

South African police have issued a “red alert” to border posts to prevent Grace Mugabe, the first lady of Zimbabwe, from leaving the country amid claims that she offered cash to her alleged victim to drop accusations of assault.

Gerrie Nel, the lawyer who is providing pro-bono representation for Gabriella Engels, said on Thursday that his client would launch a private prosecution against Mrs Mugabe if South African police did not bring a case.

"From our point of view, we would expect at least a trial, or action within three months," Mr Nel, who previously led the prosecution of convicted murderer and blade runner Oscar Pristorius, at a press conference in Pretoria. 

He said a private prosecution could result in the "exact same sentences" as in a trial brought by the state. "Any sentence is possible. Also jail time."

He added that the family had rejected an offer, allegedly made via a third party, to drop the case in exchange for cash.

Miss Engels, a twenty year old model and nightclub hostess, has accused the Zimbabwean first lady of assaulting her with an extension cord at a Johannesburg hotel where Mrs Mugabe’s sons rent flats. 

The alleged assault on Sunday night spiraled into a diplomatic and political scandal earlier this week after police accused Mrs Mugabe of failing to honour an agreement to hand herself in for questioning.

Instead she appears to have taken refuge in a rented mansion in a Johannesburg suburb and police have said she is seeking diplomatic immunity.

The case took a further twist on Thursday when Mrs Engels family announced they had accepted pro-bono legal assistance from AfriForum, a controversial Afrikaner-rights group.

At a press conference announcing their intentions to bring suit, Gabriella Engels sat silently, a fresh bandage covering the wound she says was caused by Mugabe's assault with an extension cord.

She refused to speak and stared forlornly at the table as her legal team answered questions for her.  

Earlier Fikile Mbalula, South Africa's Minister of Police said all borders have been notified to prevent Grace Mugabe from leaving the country before the matter is resolved.

"The SAPS (South Africa Police Service) have already put tabs in the borders in relation to her (Mugabe) leaving the country so there is no question about that. The red alert has been put," Mr Mbalula told reporters.

However, a police spokesman later said no arrest warrant had been prepared and that they they will wait for a decision about Mrs Mugabe's application for diplomatic immunity for taking a decision on further action.

Mrs Engels's legal team dismissed the retroactive request because, they said, Mrs Mugabe was in the country shopping and for medical reasons, but conceded that it might well be granted.

The negotiations over diplomatic immunity are "most probably done at the highest levels of government," said Willie Spies, an attorney affiliated with AfriForum, indicating that  Jacob Zuma, the South African president, and Robert Mugabe, the president of Zimbabwe, were handling the affair.

The moment diplomatic immunity is granted, Spies said, "she'll probably leave the country."

Mr Mugabe, 93, arrived in South Africa on Thursday to attend a regional leaders’ summit in Pretoria.

Neither Mrs Mugabe nor the Zimbabwean government have commented on the case.