The Hawks have confirmed that they are investigating Mineral Resources Minister Mosebenzi Zwane and former communications and now Public Service and Administration Minister Faith Muthambi after allegations of treason, fraud and corruption were levelled at them by the Organisation Undoing Tax Abuse.
The charges were brought by Outa in July following revelations in leaked Gupta e-mails.
Hawks spokesman Hangwani Mulaudzi would not give the details of the investigation, saying it is among the "140-plus" cases being looked into by Hawks investigators.
"[Included in the] investigations are the dossiers we have received from Outa," Mulaudzi told The Times.