Zimbabwean first lady has returned to homeland after the South African government granted her diplomatic immunity, helping her escape prosecution over allegations of assaulting a young model at a luxury hotel in Johannesburg.

Zimbabwean President Robert Mugabe and his wife Grace arrived at the Harare airport on Sunday after the head of state had attended a summit of southern African leaders in Pretoria.

South Africa’s Foreign Minister Maite Nkoana-Mashabane said in a notice published in South Africa’s Government Gazette on Sunday that Grace Mugabe was granted immunity.

The notice, signed on Saturday, recognizes “the immunities and privileges of the First Lady of the Republic of Zimbabwe, Dr. Grace Mugabe.”

Gabriella Engels, the 20-year-old mode, said Grace Mugabe had hit her on August 13 with an extension cord that cut her forehead.

South African police had been previously on “red alert” to prevent the Zimbabwean first lady from leaving the country and were waiting for a government decision on the immunity appeal.

The South African government’s decision to let Grace Mugabe leave was condemned by the country’s main opposition party, which urged a parliamentary inquiry into the appeal.

The government has “no more legitimacy in the arena of international diplomacy and displays a total disregard for the rule of law,” the Democratic Alliance posted on Twitter.

Commenting on Mugabe’s return, a group representing Engels said it would legally challenge the South African government’s move.

“We will take a long-term approach on this,” said Willie Spies, legal representative at the civil rights organization AfriForum.

“She may be back in Zimbabwe, but it may mean that she will find it very difficult to come back to South Africa in the future,” Spies added.

The Zimbabwean president’s outspoken wife has faced criticism for a fiery temper and lavish shopping expeditions.

Her rising political profile also raised speculations that she attempts to succeed her 93-year-old husband.