A former member of an elite police unit has been charged with the murder of a whistleblower who testified at a major police corruption inquiry in South Africa.

Matipandile Sotheni, 41, appeared in court accused of killing Marius van der Merwe in December last year.

Sotheni is accused of shooting dead Van der Merwe in full view of his family in a case that caused national outrage. He has not commented on the charges.

Van der Merwe, identified only as Witness D during his appearance at the inquiry, known as the Madlanga commission, had implicated police officials in the torture and murder of a robbery suspect in his testimony.

His testimony was seen as blowing the lid on the extent of police corruption at a local level in South Africa and led to the suspension of several of the officers he had named.

The Madlanga commission was established by President Cyril Ramaphosa after a senior police officer alleged that organized crime groups had infiltrated the government. This led to the suspension of South Africa's Police Minister Senzo Mchunu, who has denied having any links to criminal gangs.

South Africa's parliament is also investigating these allegations.

In addition to Van der Merwe, three of the 12 people implicated in the robbery suspect's killing have since died. Two were shot dead, while one killed himself, according to police.

The robbery suspect has been identified as Emmanuel Mbense, who died in April 2022. Van der Merwe alleged he was ordered to dispose of Mbense's body by local police chief Julius Mkhwanazi, who has since been suspended over the accusations.

Sotheni was arrested over the weekend and is one of three suspects identified in Van der Merwe's murder.

Security was tight at the court as armed officers escorted Sotheni, dressed in all black, into the packed courtroom. The former officer showed no emotion during proceedings. In contrast, Van der Merwe's grieving wife could be seen wiping away tears.

Van der Merwe's sister stated that the family believes the person who ordered his murder was "definitely someone my brother knew".

Police spokesperson Brig Athlenda Mathe said Sotheni was the alleged hitman while another suspect, Wiandre Pretorius, was the driver of the car used in the drive-by shooting. Pretorius is the suspect who committed suicide. The car has since been seized, but police are still searching for the firearm believed to be an AK-47.

Sotheni also faces charges of attempting to kill Van der Merwe's wife and children. The case has been postponed to 25 March for a formal bail application.