The Transet Group's acting chief executive officer, Mohammed Mahomedy, is expected to take the stand on Wednesday when the judicial Commission of Inquiry into Allegations of State Capture resumes in Parktown, Johannesburg.
After probing state-run power utility Eskom, facilities management company Bosasa and other entities, the inquiry turned its attention to freight rail group Transnet in early May.
The group's chairperson, Popo Molefe, earlier testified that Transnet was ground zero for state capture. He said corruption at Transnet was "endemic".
Molefe referred to former executives, Brian Molefe, Siyabonga Gama and Anoj Singh, as the "architects of capture".