The FBI in the U.S. has begun a probe into the Guptas, investigating their links with American companies.
The Financial Times reported that the investigators have, in recent months, started probing individuals, bank accounts, and companies in the US for ties to alleged misconduct involving the Guptas.
The US investigation is reported to draw on information from masses of emails leaked from within the Gupta corporate empire earlier this year, now commonly known as the Gupta Leaks.
The Financial Times said the FBI is focusing its investigation on Ashish and Amol Gupta, who are nephews of the Gupta brothers, Ajay, Atul and Rajesh.
The Guptas reportedly sought to employ their nephews in South Africa in 2013 and Tax records in Texas name Ashish and Amol Gupta as directors of Brookfield Consultants Inc, a Houston-based company.
Brookfield allegedly received payments to a U.S. bank account from Accurate Investments, a United Arab Emirates company tied to the Gupta family, in 2014, according to documentation seen by the Financial Times.