All eyes are expected to be on PricewaterhouseCoopers (PwC) forensic auditor Trevor White on Monday when he takes the stand at the state capture commission of inquiry.
In a statement on Sunday, the commission said the testimony would relate law enforcement.
While it is unclear what exactly White's testimony will concern, he was previously mentioned in the testimony of ex-policeman Major General Johan Wessel Booysen in 2019 as someone who was involved in investigating what has become known as the 'Amigos case'.
The case relates to tenders for the supply of water purification and oxygen plants to the province's health and local government departments.
It dragged on for years and involved political heavyweights, Mike Mabuyakhulu and Peggy Nkonyeni and others accused of racketeering, corruption and fraud.
Eventually, the charges were withdrawn.
Booysen said he inherited the case in 2010 from the Commercial Crimes Unit in KwaZulu-Natal.
According to Booysen, the investigating officer in the case, Lieutenant Colonel Piet du Plooy said he and White were summoned by then Special Director of Public Prosecutions Lawrence Mrwebi and advocate Anthony Mosing.
"Du Plooy informed me that it was evident that the two advocates had aligned themselves with the notion that the case against Nkonyeni and Mabuyakhulu did not have sufficient evidence to proceed against them," Booysen told the commission.
He added, however, that Du Plooy had nonetheless assured him that there was "a prima facie case against the two".
The case was reassigned to another prosecutor and "since then, no prosecutions have been reinstituted on these charges against Nkonyeni and Mabuyakhulu," Booysen said.
News24 previously reported that suspended deputy prosecutions boss Nomgcobo Jiba allegedly told then KZN acting director of public prosecutions Simphiwe Mlotshwa that they should "cut their losses" when it comes to some witnesses in the case.
White had also been involved in PwC's global economic crime survey in 2018 which found that South African organisations continued to report the highest instances of economic crime in the world, Fin24 reported.
White found that 77% of South African organisations experienced economic crime - results White said were dismal and revealed the highest level of reported fraud and economic crime since the survey was launched in 2001.