Talk Radio 702 on Wednesday quoted a Hawks spokesman saying the unit would investigate graft allegations, after a complaint was made by the Democratic Alliance (DA), South Africa's main opposition party.

“I have now received notification that the South African Police Service have allocated a case number...and transferred the case for further investigation to the anti-corruption unit within the Directorate of Priority Crime Investigation," the DA's finance spokesperson David Maynier said in a statement.

The DA said Monday its charge of corruption against Atul Gupta, Ajay Gupta and Duduzane Zuma had been referred to the Hawks for investigation.

Matthews Phosa, a former treasurer of Zuma's ruling African National Congress (ANC), claimed Wednesday there was evidence of an "unhealthy relationship" between the Guptas and Zuma.

'Guptagate' cannot be 'swept under carpet anymore'

The Gupta family owns a business empire that includes computer equipment, media and mining interests. It is alleged by the Rand Daily Mail to have worked closely with Zuma to secure interests in South Africa's nuclear energy sector and to have supported him during his fight for the leadership of the ANC with then-president, Thabo Mbeki, in 2005.

The current scandal, commonly dubbed Guptagate, has been ongoing for some time, but escalated last week when Zuma denied suggestions the Guptas had been behind his sacking of finance minister, Nhlanhla Nene, in December.

"The issue cannot be swept under the carpet any more and it looks like the tide has turned against the role of the Guptas in the country's public life and business linkages," Daniel Silke, a South Africa analyst told DW. "Zuma has been weakened by association, but he survives to fight another day. It's difficult to quantify what the Guptas' exact influence is, but the African National Congress (ANC) and the public prosecutor will no doubt now aim to assess this."

Zuma's son, Duduzane, is a director - along with Gupta family members - of at least six companies, most of them reportedly owned by the Gupta family.

The family itself has said it would welcome a formal investigation, if it could end what it called a "trial by innuendo and slander." They have denied having any role in government appointments, saying they are pawns in a plot to oust Zuma.

The Indian-born Gupta family moved to South Africa at the end of apartheid in the early 1990s. Zuma has said he has strong links to the family, but denies any of his decisions have been motivated by this.

The ANC on Tuesday denied reports that President Jacob Zuma had offered to resign after mounting claims of improper political interference by the leader's wealthy business friends. Earlier, the ruling party had said it would investigate alegations from politicians saying that they were offered positions by the Guptas.

The ANC, which has been in government since 1994, faces a test of support at local elections in May.

jbh/msh (Reuters, AFP)