Another person has been arrested in connection with the R2.2-billion Kusile corruption case.

The suspect was expected to appear at the Middelburg Specialised Commercial Crimes Court in Mpumalanga on Wednesday morning.

"The accused stands charged with money laundering linked to Kusile Power Station in Mpumalanga. He joins 16 other companies and persons arrested and charged in the same case," said Investigating Directorate (ID) spokesperson Sindisiwe Seboka.

One of the companies implicated in the case is Swiss engineering firm ABB.

The Special Investigating Unit (SIU) previously said its investigations revealed that ABB subcontracted Impulse International, a company owned by former Eskom group CEO Matshela Koko's stepdaughter, Koketso Choma, and other companies.

"Evidence obtained by the SIU revealed that Mr Koko allegedly played a vital role in the awarding of contracts to Impulse International, ABB and other sub-contractors.

"When contracts were awarded to Impulse, his stepdaughter became a director at Impulse and she later resigned [from] her directorship in Impulse and opened Mokoni Trust.

"Monies were then paid into the Trust by Impulse. The monies were then channelled to businesses and various channels linked to the Koko family," said SIU spokesperson Kaizer Kganyago.