The Department of International Relations and Cooperation has confirmed that Minister Maite Nkoana-Mashabane had granted Zimbabwe First Lady Grace Mugabe diplomatic immunity.
Mugabe is at the centre of an assault claim in South Africa.
"I hereby recognise the immunities and privileges of the First Lady of the Republic of Zimbabwe, Dr Grace Mugabe," reads a Government Gazette notice, signed by Nkoane-Mashabane on Saturday and published on Sunday.
In the "Minister's Minute", it indicates that she makes the recognition "in accordance with the powers vested in me by section 7(2) of the Diplomatic Immunities and Privileges Act 2001 (Act No 37 of 2001) and acting in the Interest of [the] Republic of South Africa".
It goes on to indicate that the immunities and privileges of Mugabe are recognised "in terms of international law and as set out in the attached Notice".
Dirco spokesperson Nelson Kgwete confirmed the authenticity of the notice and said the department would release a statement later in the day.
Earlier on Sunday, various reports emerged that Mugabe had flown back to Zimbabwe that morning with her husband, President Robert Mugabe.
This month, a case of assault was reported to police by model Gabriella Engels who claims Grace Mugabe attacked her with an extension cord at a Sandton Hotel on August 13.
On Friday, the police's Vish Naidoo told Netwerk24 that police had provisionally halted investigations into the matter after a note verbale was received, which indicated that the suspect in the case had applied for diplomatic immunity.
Meanwhile, earlier on Sunday, Afriforum said it would approach the courts to contest the diplomatic immunity.
"What we will carry on with is a review application [of the decision] to grant her immunity," said Afriforum's legal representative Willie Spies.
"We believe that it is not a correct decision," he said, adding that his organisation believes that this was in contravention of South Africa's laws, as well as the rights of the victim to see justice.
Depending on the outcome of a review, Afriforum was also keen to "eventually carry on with a private prosecution".
Furthermore, he suggested that it might become "very difficult" for Mugabe to return to South Africa in the future, suggesting that she could be considered "for all intents and purposes: a fugitive".