Special Investigating Unit

The Special Investigating Unit (SIU) is an independent agency of the South African government which investigates corruption and maladministration in state institutions. It was first established in July 1997 by President Nelson Mandela, although it has not operated continuously since then. As of 2022, the SIU was headed by Advocate Andy Mothibi and had its headquarters in Meyer's Park, Pretoria.

Its primary mandate is to provide anti-corruption, forensic investigation, and litigation services to combat corruption, serious malpractice, and maladministration in state institutions. It therefore not only investigates cases but also is empowered to take civil action to correct wrongdoing which it uncovers, including by recovering financial losses suffered by the state. It also has the power to subpoena witnesses, bank statements, and cellphone records; powers of search and seizure; and power to interrogate witnesses under oath. However, it is required to refer evidence of criminal conduct to the National Prosecuting Authority.