The Organisation Opposing Tax Abuse (Outa) plans to go to court in an attempt to freeze a Gupta account where the rehabilitation funds for their Optimum and Kroonfontein mines are held, The Times reported on Friday.
An urgent application will be brought in the Pretoria High Court.
On Thursday, the Guptas lost an application to stop the Bank of Baroda from closing their accounts. All their accounts will now be closed, including the one where the rehabilitation funds for the mines are held. Outa is reportedly afraid that the R1.75 billion kept in the account will go missing.
The money is for the rehabilitation of the areas around the mines.
Outa chief operating officer Ben Theron told The Times that Outa wanted assurances from Mining Minister Mosebenzi Zwane that the money was safe, but this had not been forthcoming.
"The account must be frozen until assurances are given by Zwane that the ministry will appoint decent trustees," he reportedly said.
Theron also said that Outa believed that the CEO of the Guptas' company Oakbay, Ronice Ragavan, ran the fund, and that this was "unacceptable".
According to Fin24.com, the Bank of Baroda told the court it was afraid of reputational damage, and this is why it had to close the accounts. Twenty companies belonging to the Guptas brought the application to stop the closure of the accounts.
Four of South Africa's biggest banks also closed the Gupta accounts, as well as the Bank of China.