The Parktown office of the state capture commission of inquiry was burgled on Saturday night.
News channel eNCA reported items such as laptops were stolen. According to the channel, the burglary was discovered on Sunday morning.
Commission spokesperson Mbuyiselo Stemela confirmed the break-in, saying two computers were stolen.
"The police are busy with investigations. The public hearings are not affected at all and will continue tomorrow despite the break-in," Stemela added.
Gauteng police would not confirm the incident.
"I can neither confirm nor deny the incident," spokesperson Colonel Noxolo Kwaza told News24.
The commission, led by Deputy Chief Justice Raymond Zondo, began its work in 2018. It is investigating allegations of corruption and state capture and is hearing testimony from, among others, government departments and state-owned enterprises.
On Sunday, the commission said it would issue a detailed statement regarding the incident in due course.
Meanwhile, in a statement on Sunday, it said it would hear parliamentary oversight-related evidence on Monday from National Assembly Speaker Thandi Modise and Amos Masondo who is the chairperson of the National Council of Provinces.
ANC chairperson Gwede Mantashe is expected to testify later on Monday afternoon.