Friday marked the sixth day of more damning correspondence between the family, their associates, government ministers and board members of public enterprises emerging in media reports likely to continue apace as investigative reporters wade through an estimated 100,000 to 200,000 missives put at their disposal on an internet platform.
The latest leaks suggest that Salim Essa, known for trying to buy a bank after the Guptas's accounts were closed and heading Denel's red-flagged joint venture partner VR Laser Asia, was allowed to vet Ben Ngubane's first public statement as Eskom chairperson two years ago.
Reports on Friday quoted from an email in which Nazeem Howa, the then CEO of the Guptas' Oakbay Holdings, attached a draft of Ngubane's speech in March 2015 for Essa's approval.
The reports come two days after Ngubane was ordered to rescind his reinstatement of Brian Molefe as group CEO of Eskom and puts more pressure on the chairperson and the board, after former finance minister Pravin Gordhan bluntly suggested a fortnight ago that they resign for failing the country.
Molefe arrived at Eskom weeks after Ngubane and won credit for ending load-shedding.
But last year Molefe's reputation dimmed to that of a key player in public sector collusion with the Guptas after the Public Protector's report on state capture zoned in on Eskom's coal contract with the family's Tegeta Exploration.
Gordhan had in the same breath as berating the Eskom board raised questions about business dealings between the Gupta business empire and Transnet, which has been at the centre of the week's leaks, during Molefe's earlier tenure at the freight company.
From the leaked emails, the amaBhungane investigative reporting team gleaned the details of how the family came to pocket almost R10 million for every R50 million Transnet paid for a Chinese-built rail locomotive.
This reportedly flowed from a contract given to Tequesta, a company set up by Essa and mandated to help China South Rail win a contract to supply 359 locomotives to Transnet.
As with VR Laser Asia, Essa was the sole shareholder in the company. Essa succeeded and secured an advisory fee of 21 percent, or R3.8 billion, of the R18.1 billion deal.
Further reports on Transnet have also cast a cloud overly newly-minted Finance Minister Malusi Gigaba with suggestions that while he held the public enterprises portfolio, he imposed Iqbal Sharma as a member of the company's board.
Sharma is said to have facilitated the arrangement through which Tequesta became the agent for the locomotive deal.
Gigaba's name crops up repeatedly in the leaks, which also link him to Gupta associates while he served as home affairs minister.
The Daily Maverick cited a chain of emails in which it is claimed that Gigaba ordered two officials to be placed in Mumbai and New Delhi to fast-track visas for the Guptas as they shifted assets and employees between India and South Africa.
The South African Communist Party has called on the minister to resign, saying he has now lost the benefit of the doubt it was still prepared to give him two months ago when he replaced Gordhan as the political head of the treasury.
"Quite clearly, the majority of those who are affected, they should not hold public office on our behalf. And I think it is as easy as that. That includes the current Minister of Finance Malusi Gigaba," the SACP's second deputy secretary general Solly Mapaila has said.
"Otherwise, there's no way that our people can trust government with such people at the helm."
The emails also back up reports that Bell Pottinger was paid to cast criticism and suspicion of the Guptas and their ties to Zuma and the State as a plot by "white monopoly capital", a term that has, with or without the help of the UK-based PR firm, become baseline political rhetoric.
One email sees Bell Pottinger's financial and corporate head, Victoria Geoghegan advise ANC Youth League leader Collen Maine ahead of a national rally in February 2016.
And in other correspondence, Anda Bici, a communications handler for the ANCYL, ask Atul Gupta for funding for the organisation.
If the emails implicate ministers and captains of state enterprise and hint that the Guptas were in the loop about the appointment of Mosebenzi Zwane as mineral resources minister, they do not explicitly confirm consistent claims that Zuma takes direction from the Gupta brothers.
On Thursday, the president told Parliament state capture was simply a rumour. Earlier in the week it became apparent that he would not give up the fight to determine who, if anybody, is appointed to head a commission of inquiry to further probe the findings contained in last year's "State of Capture" report.
But on Friday, Business Day reported that his son Duduzane, who owns almost half of Tegeta, arranged a meeting between the president and the chairman of Russian Investment company Sistema Joint Stock Financial Corporation, Vladimir Evtushenkov, in Davos.
In one email obtained by the newspaper, a managing director of the Russian company thanks Duduzane for facilitating friendly, "productive" talks.
It raises questions as to whether the younger Zuma benefits financially from the contacts he introduces to his father, and what impact his business partnerships with the Guptas may have on executive decisions.
The trove of emails may yield answers, as well as further questions, and will haunt the Zuma camp in a torn ANC and their bid to impose Nkosazana Dlamini-Zuma as the next head of the party until December, and may well help that of Ramaphosa.
If ANC secretary general Gwede Mantashe's call for a judicial commission of inquiry into state capture sounded like an impotent plea after the failed attempt at last weekend's National Executive Committee meeting to force Zuma to step down, it will increasingly resonate as the voice of reason as more leaked evidence of corruption emerges.