The official opposition Democratic Alliance (DA) on Tuesday urged President Cyril Ramaphosa to sanction former International Relations and Co-operation Minister Maite Nkoana-Mashabane in the wake of the high court ruling overturning her decision to extend diplomatic immunity to Zimbabwe's former first lady Grace Mugabe.

The Johannesburg High Court found the decision to give Mugabe immunity when she was accused of assaulting a young South African in 2017, unlawful and unconstitutional.

James Selfe, the chairman of the DA's federal executive said the judgment was an indictment of the minister.

"Ms Nkoana-Mashabane seems to have been acting on questionable legal advice in opposing the DA’s application, and clearly put expedience ahead of constitutionalism and international law," Selfe said.

"The DA has always contended that Mugabe was granted immunity by the ANC-led government in order to shield her from being tried in a South African court of law for her alleged assault of Ms Gabriella Engels."

The court held that the wife of former Zimbabwean president Robert Mugabe was not immune from the jurisdiction of South Africa's courts.

The immunity conferred on her was challenged by the DA and civil rights group Afriforum.

Selfe said his party would write  to the National Prosecuting Authority (NPA) to ask that it issue a warrant for Mugabe's arrest.

"Grace Mugabe deserves her day in Court and it is essential that the ANC-led government engages with all relevant stakeholders to ensure that she returns to face the full extent of the law.  We cannot have a government which abuses and bends the law at the expense of justice for its own citizens."

Mugabe was given immunity in August last year after Engels accused her of beating her with an electrical cord in a hotel room in Johannesburg.