Gupta allegedly told Jonas that his family made six billion rand ($444 million) from the state, and wanted to increase it to eight billion rand.
Calls for South African President Jacob Zuma to resign reached new heights Wednesday after a much-awaited probe was published into his allegedly corrupt relationship with the Guptas, a business family from India.
Here are five key points from the report by the Public Protector watchdog:
Deputy Finance Minister Mcebisi Jonas said he was taken to the Guptas' compound-like residence in the Saxonwold district of Johannesburg by President Zuma in October 2015.
The report said Ajay Gupta first accused him of undermining Zuma, then "informed Mr Jonas that they were going to make him Minister of Finance".
Gupta allegedly told Jonas that his family made six billion rand ($444 million) from the state, and wanted to increase it to eight billion rand. The report gave no time frame.
When Jonas refused the apparent job offer, Gupta offered him 600 million rand and even "asked if Mr Jonas had a bag which he could use to receive and carry 600,000 rand in cash immediately".
The report said it was "worrying" that telephone records revealed David Van Rooyen, then a little-known Zuma loyalist, was regularly in Saxonwold, including on the day before he was appointed as finance minister last year.
One of the two advisers that Van Rooyen took with him to the treasury on his first day at work as finance minister had also had telephone contact with someone in Saxonwold the previous day.
"The coincidence is a source of great concern," the report said.
Van Rooyen lasted just four days in the job due to a market crash triggered by his appointment. But he is still one of Zuma's closest associates.
The report raises allegations that Mining Minister Mosebenzi Zwane travelled to Switzerland with the Guptas last November to help them "seal the deal" for Gupta-owned company Tegeta to buy a mine from Glencore.
Zwane's conduct "with regards to his flight itinerary to Switzerland appears to be irregular", the report said.
Zwane's spokesman said the minister's visit to Switzerland was for "engaging with stakeholders and to avoid job losses".
The Guptas told the report authors that Brian Molefe, chief of state-owned electricity firm Eskom, was a "very good friend" who often visited them at home.
The report details allegations of deals during which "it appears that the conduct of the Eskom board was solely to the benefit of Tegeta in awarding contracts to them".
The Public Protector's office vowed further investigations into contracts for Tegeta to supply coal to Eskom.
The report listed remedial action including Zuma appointing a commission of inquiry that must present its findings within 180 days.
It said the inquiry must be well-funded, chaired by a judge who chooses their own staff, and given real power to collect evidence.