"I look forward to meeting them in court", was former ANC MP Vytjie Mentor's message to the Gupta family after they challenged her to provide proof that they offered her a Cabinet position in 2010.
Mentor took to Facebook on Thursday morning to respond to the politically connected family's statement denying the allegation.
"I do have a trump card!!![sic]," she wrote.
"I can corroborate my claim. Legal threats don't scare me. I have no money like they do. I have only the TRUTH as my valuable possession."
Mentor referred to herself as David fighting Goliath, who she said was the Guptas.
"I am ready, very ready."
Details of visit
On Monday night, while on holiday in Thailand, Mentor claimed that the Guptas offered her the job of Public Enterprise Minister and the time when Barbara Hogan was removed from the position.
Mentor arrived back in South Africa on Wednesday.
She also claimed that President Jacob Zuma was in another room at the family's Saxonwold mansion when the offer was made.
However, Zuma has denied this, going as far as saying he has "no recollection" of Mentor.
The Gupta family on Tuesday challenged Mentor to file an affidavit stating under oath that she was offered a ministerial position by them.
In a second post on Thursday morning, Mentor provides some details of her visit to the family's home and her interaction with Zuma while there.
Mentor insists that Zuma was at the Gupta house with her on the day the offer was made.
"He came in after I rejected the offer. He accompanied me down the 4/5/6 marble (covered) wide stairs at the entrance of the Gupta house to their black twin-cab with heavily black-tainted windows which taking me back to the airport," she wrote.
Mentor said she was on crutches at the time and it was five to seven days before Hogan was removed.
"The rest I will reveal at the right time."
On Wednesday, Deputy Finance Minister Mcebisi Jonas confirmed that the Guptas had offered him the job of finance minister last year before Nhlanhla Nene was removed.
The Guptas have again denied this and called Jonas a liar. They have also challenged him to provide proof of the meeting.
Zuma has not responded to Jonas's revelation.