Updated

Zimbabwe's President Robert Mugabe has arrived in South Africa as his wife is accused of assaulting a young model.

Mugabe flew into Waterkloof Air Force Base in Pretoria with his entourage late Wednesday night, apparently to help his wife with the ongoing scandal. The Zimbabwean president arrived early for a regional summit of southern African nations.

The model who accuses Zimbabwe's first lady of assault has been offered legal assistance by a prominent lawyer who secured the murder conviction of Oscar Pistorius.

Gerrie Nel, a former state prosecutor who now works as a private prosecutor for AfriForum, an organization that primarily represents the rights of South Africa's white Afrikaner minority, said he will offer help to Gabriella Engels, the 20-year-old woman who filed a complaint of assault against Grace Mugabe. Nel, known for his tenacious in-court cross-examinations, will appear Thursday with Engels at a press conference.

South African officials are considering whether to grant Mugabe, 52, diplomatic immunity which she has requested to avoid facing the assault allegations.

South African police told local media they are awaiting instructions from the Department of International Relations and Cooperation on how to proceed with the case. A spokesman from that department declined to comment on the status of Mugabe's immunity bid on Thursday, but said on Wednesday the matter was under consideration.

It is unclear whether Mugabe entered the country in a personal or an official capacity, which could impact her immunity appeal, but Zimbabwe's state-owned Herald newspaper reported last weekend that she was in South Africa seeking medical care.

The debate over whether Mugabe should be granted immunity quickly took on a political dimension in South Africa, with the opposition Democratic Alliance calling on the President Jacob Zuma's cabinet to ensure Mugabe is brought to justice.

"Ms. Mugabe should have applied for diplomatic immunity before she came to our country, not after she finds herself facing criminal charges," the DA's Zakhele Mbhele said in a statement.

The police minister "needs to do his job and ensure she is arrested and has her day in court to answer the serious charges against her."