The US Central Intelligence Agency (CIA) in 2009 alerted South African state intelligence structures to the potential threat of the Gupta family, a Sunday newspaper has reported.
Former intelligence officials Gibson Njenje and Moe Shaik told the Sunday Times that they had been involved in a probe into the Guptas.
Njenje told the newspaper he was contacted by US officials in 2009 querying the Guptas' interest in uranium mining. In that year, the Gupta-owned Oakbay Resources had purchased Uranium One's Dominion mine.
Enriched uranium is linked to the manufacture of nuclear power and weapons.
The CIA wanted to know the reasons behind the Guptas' interest in producing the substance, as well as their intended target market, the report said.
Njenje and Shaik told the Sunday Times that they were alarmed when they unravelled the seemingly extensive influence of the Guptas on former president Jacob Zuma's first Cabinet reshuffle in October 2010.
Njenje said the Guptas were beginning to meet with government officials and were allegedly openly showing their ties with Zuma, such as in organising arrangements for state visits.
It also emerged at the time that Zuma was frequently visiting the Guptas at their compound in Saxonwold.
However, according to the newspaper, while Njenje and Shaik met with Zuma several times, he did not appear interested in warnings against the Guptas.
Shaik told the Sunday Times that at the time, Zuma had told him that the Guptas were the only ones who would assist his son.
Former communications minister Siphiwe Nyanda, who was fired in the 2010 reshuffle, is quoted in the newspaper as confirming that he once received a visit by Zuma's son Duduzane, as well as the Gupta brothers.
At the time, they reportedly told him they just wanted to introduce themselves since they were working in the communications sector.
All three men said they would be willing to testify at the ongoing Commission of Inquiry into State Capture.
Former deputy minister of finance Mcebisi Jonas told the inquiry on August 24 that one of the Gupta brothers told him that they "control everything" and were in charge of the NPA, Hawks and National Intelligence.
On Sunday, Njenje and Shaik confirmed to News24 the veracity of their comments to the newspaper - but declined to add anything further.
The State Security Agency said it would release official response to the report later on Sunday.
SSA spokesperson Lebohang Mafokosi responded to News24's request for comment on Sunday afternoon.
"The State Security Agency is not in a position to confirm or deny the information as the Agency does not discuss operational matters with the media," Mafokosi said via email.
"The general practice of intelligence liaison is that discussions with counterparts are confidential and can not be divulged to third parties. As such, the Agency is not able to disclose such information."
*This story has been updated to include the SSA's comment.