Former Eskom executive (Head of Generation, Acting Group CEO). Linked to the ABB/Impulse International kickback scheme at Kusile. ABB awarded an irregular R2.2B contract and subcontracted Impulse International, owned by Koko's stepdaughter Koketso Choma. ABB settled for R1.577B. Koko resigned from Eskom in 2018. SIU investigation ongoing; no criminal conviction.