Des van Rooyen visited the Gupta family compound not just once, but seven times, in the days before his appointment as finance minister by President Jacob Zuma in December last year.
The visits, on consecutive days between December 2 and 8, have been revealed by a team of public protector investigators tasked with probing alleged state capture by the family.
The BBC previously reported that cellphone evidence put Van Rooyen at the Guptas' Saxonwold house on the night before his appointment. Now the Sunday Times has learnt that the minister visited the family for an entire week.
The investigators used cellphone records to track Van Rooyen's whereabouts in the days preceding Zuma's decision to appoint him in place of Nhlanhla Nene.
The revelations emerged as a trail of e-mails surfaced linking Van Rooyen, now co-operative governance minister, to a Gupta-linked company.
The e-mails are between Van Rooyen, his adviser Ian Whitley and Trillian Capital Partners CEO Eric Wood. They confirm a whistleblower's account that Wood knew two months before Van Rooyen's appointment that Zuma intended to fire Nene.
Zuma appointed Van Rooyen as finance minister on December 9, but negative reaction and turmoil in the markets forced the president to renege.
The public protector's investigation reveals that Van Rooyen also spent the night before the announcement of his four-day appointment "drinking tea with the Guptas" at their home.
The Sunday Times has learnt that evidence submitted to former public protector Thuli Madonsela also shows that one of Van Rooyen's advisers, Mohammed Bobat, visited the Gupta residence on one of the seven days the minister was there.
Bobat is former principal at Regiments Capital. He was made a special adviser to Van Rooyen, allegedly to advance the agenda of the Guptas' business associates, Salim Essa and Wood.
One of the investigators told the Sunday Times that Madonsela's office received the evidence just days before she was served with two separate notices by Zuma and Van Rooyen to interdict her report.
"We strongly suspect a mole within our office leaked the crucial information, which prompted the interdict notice that stopped Thuli from releasing the state capture report," the source said.
He said the investigation had been done "by the book" and confirmed that Van Rooyen had been tracked to the Gupta residence. But he declined to give details of how they had accessed Van Rooyen's cellphone records.
Zuma's interdict application is due to be heard at the High Court in Pretoria on Tuesday. Van Rooyen withdrew his application last week, saying Madonsela had not made any adverse finding against him.
In her questions to Van Rooyen, which were part of his court application, he said Madonsela asked him to explain his "frequent visits" to the Gupta residence and his arrival at the Treasury with several advisers who included Whitley and Bobat.
Whitley, who is now chief of staff in Van Rooyen's department, is the son-in-law of ANC deputy secretary-general Jessie Duarte. Duarte said she did not have a role in Whitley's appointment.
Van Rooyen's spokesman, Legadima Leso, said: "Insinuations that the minister's appointment was influenced by any person other than the president is totally unfounded."
Leso refused to answer any further questions.
Madonsela declined to comment on Van Rooyen's telephone records.
"The court order is such that we can't discuss the matter," she said.
Van Rooyen's office also failed to respond to questions about the e-mails.
In one of the e-mails, written on October 26, about two months before Zuma's announcement, Wood, a business partner of Essa, details priorities for the finance minister.
Essa is a well-known Gupta business associate who has directorships in many of their companies.
Trillian said this did not make the company Gupta-linked. It also denied any wrongdoing.
Wood's e-mail to Essa is headlined "National Treasury 26 October". It advised Essa that Wood had prepared some pointers for the finance minister.
It said: "Hi Salim ... as discussed, I have quickly jotted down a few points for the FM. These are not comprehensive - in time I'm sure I can develop a more comprehensive list ... regards Eric."
This was just three days after the Guptas, who had allegedly been shopping for Nene's replacement, were turned down by Deputy Finance Minister Mcebisi Jonas.
Wood's e-mails confirm a whistleblower's version that was published in the Sunday Times last week.
The whistleblower, who is a former CEO of one of Trillian's subsidiaries, claimed in an affidavit to Madonsela that Wood had told her on October 26 that Nene would be fired.
In the e-mail to Essa, Wood attached a document with the title "National Treasury Discussion Points - Key Initiatives". These appear to be suggestions of priorities for the finance minister.
Among the eight points contained in the document was that the Treasury should help tier-two municipalities to access debt in the capital markets. This would be used to pay for infrastructure projects while providing the municipalities with collateral for loans.
In the e-mail, Wood also suggested that a South African national black bank should be established. All the state institutions would use the bank, even to pay employees. The state would then be able to dump commercial banks.
Nene, who was finance minister at the time, said this week that he never had any discussions with Essa, Wood or Trillian between October last year and his removal in December.
A few days after Van Rooyen's four-day stint at Treasury ended, he sent an e-mail to Whitley. The detail of the e-mail suggests he was privy to Wood's earlier proposals.
At 6.40am on December 15 2015, Van Rooyen wrote: "Morning and Thx Ian, pls solicit Eric's input on usage of municipal/household assets for collaterisation. Will discuss my inputs this morning."
The use of municipal assets for collateral was part of the eight initiatives which were sent to Essa by Wood in October.
Later that morning Bobat, the second of Van Rooyen's advisers, wrote to Wood: "Hi Eric. I've given him the feedback re debt which you and I spoke about."
Wood did not respond directly to questions and said the matter was part of an independent investigation by Trillian chairman Tokyo Sexwale.
A statement by the company said: "You are encouraged to participate in this process and, where required, with the country's law-enforcement agencies. The company and its chief executive officer strongly deny any wrongdoing whatsoever. Trillian wishes to reiterate that it is confident that it has only invoiced for work done to the satisfaction of the client in terms of the contract with the client."
The e-mails form part of a civil court matter between Regiments directors Litha Nyhonyha and Niven Pillay against their former partner Wood. Nyhonyha and Pillay, in their application, say that the cession of contracts from Regiments to Trillian was illegal. They also accuse Wood of sharing company secrets with Essa after they had refused to sell the majority of Regiments shares to the Guptas.
Last week the Sunday Times reported that the company was drawn into the public protector's investigation of state capture by the Gupta family, after a former employee revealed that she had been informed by Wood about the impending change of finance minister two months before it happened.
In reaction, the company has called the employee a thief and a fraud. It said her affidavit had never been tested in a court of law.
"Trillian is satisfied that it has the documentary evidence to prove the allegations contained in ... affidavit as inaccurate," the company said.