JOHANNESBURG - The Ahmed Kathrada Foundation believes there's more to Marius van der Merwe's death than meets the eye.
Van der Merwe, who testified at the Madlanga Commission as Witness D, was assassinated on Friday night.
A candlelight vigil was held at his home in Brakpan.
"Corruption kills, irrespective of what the minister thinks, it’s the media and whoever else, bottom line is corruption kills, whether it’s related to zama zamas, or irregularities in Ekurhuleni," said the foundation's Neeshan Balton.
"He joins a long list of people."
Defend Our Democracy says the killing of whistleblowers must stop with Van der Merwe.
"The pattern of telling the truth, costing a life has reached unbearable proportions in South Africa," said Naledi Kuali.
"People are being told that corruption is being taken seriously, and we need to see legislative reform."