President Robert Mugabe kisses first lady Grace Mugabe during Zimbabwe's 37th Independence Day celebrations in April.
Johannesburg CNN  — 

Zimbabwean first lady Grace Mugabe returned home Sunday from South Africa, where she was accused of assaulting a model with an electric cord, public broadcaster ZBC reported.

ZBC said on its website that President Robert Mugabe, “who was accompanied by the first lady, Grace Mugabe, Finance and Economic Development Minister, Patrick Chinamasa and Foreign Affairs Minister, Simbarashe Mumbengegwi arrived aboard an Air Zimbabwe plane in the early hours of today.”

Mugabe was able to leave South Africa after its government approved her request for diplomatic immunity.

The alleged attack on Gabrielle Engels, 20, took place at a hotel in Johannesburg’s posh Sandton district on August 13.

In making the decision, South Africa took into account the need to maintain good relations in the region and with Zimbabwe in particular, said International Relations and Cooperation Minister Maite Nkoana-Mashabane in a statement.

“The Minister has made the determination that the conferring of diplomatic immunity is warranted in this particular instance,” the statement said.

“The Department wishes to convey the message that the Minister has agonized over this matter and the decision was not an easy one to make.”

Read: Grace Mugabe asks for diplomatic immunity

According to Engels, she was in a hotel room with Mugabe’s two adult sons when the attack took place.

“Rob jnr was put out of the hotel room and Bellermine ran away” Engels wrote in a tweet, referring to Mugabe’s sons. “My two friends and I were beat up in a room with 10+ men leaving her to do it.”

Engels also claimed on Twitter that Mugabe “split my head open in 3 places. With an extension cord and plug to hit me.”

Police initially said Mugabe had turned herself in before revealing that she had not. Her attorneys and representatives of the Zimbabwean government met police last Tuesday to establish “channels of cooperation,” police said.

The Mugabes had flown to South Africa to attend a two-day regional leaders’ summit in Pretoria. But Grace Mugabe had not been seen since the allegations were made and failed to appear at the Pretoria summit.

South Africa's former prosecutor Gerrie Nel is taking up the case.

Engels is being represented by South Africa’s legendary prosecutor Gerrie Nel, who led the murder case against the athlete Oscar Pistorius. Nel now works for the Afrikaner rights group AfriForum.