The South African Communist Party (SACP) on Sunday called for the Hawks and National Prosecuting Authority (NPA) to investigate the leaked emails, which purportedly show ties between President Jacob Zuma, his son Duduzane and the controversial Gupta family.

"The most immediate threat that we are facing is the Gupta linked parasitic network," SACP secretary general, Blade Nzimande told reporters in Johannesburg.

Nzimande was addressing the media following the party's central committee which has been meeting since Friday.

He told the media that the Gupta links emails appeared to look genuine.

Nzimande said no-one had come out to say the emails were false and that no action had been taken against the media as yet.

The emails leaked to the Sunday Times and City Press indicate that the family has influence over Zuma, his family, Cabinet and several state-owned entities.

'Parasitic plundering'

The family allegedly offered former finance deputy minister, Mcebisi Jonas, and former African National Congress (ANC) MP, Vytjie Mentor, Cabinet posts.

The emails have also alleged that Zuma and his family have an intention to leave SA and settle in Dubai.

Nzimande said it didn't "look good" that Zuma and his son were implicated in the leaked emails.

"We can no longer just fool around when in fact the country is faced with what is potentially a very serious threat," he said.

He added that "the sheer scale of corporate capture and parasitic plundering of public resources by the Gupta network becomes more and more evident.

"Sadly, and even more concerning, the central role of President Zuma and his son Duduzane in this auctioning off our national sovereignty is also increasingly apparent.

"An independent judicial commission of inquiry into state capture should be established, immediately."

He also added that "dark threats" had been made in the ANC NEC meetings.

"The issue of threats doesn't start now. People have died in KZN, councillors have been killed. Once you start making physical threats then that means you have run out of ideas," he said.

Nzimande said the rate at which the ANC was declining, the party may not retain its electoral majority in 2019 and that further organisational fragmentation cannot be ruled out.

The SACP is preparing for its elective conference in July, at which it would likely decide whether or not to contest the 2019 elections on its own, instead of backing the ANC.