Brett Kebble, a member of Thabo Mbeki's ruling ANC and a key supporter of the recently sacked deputy president Jacob Zuma, was killed on Tuesday evening as he drove his Mercedes through northern Johannesburg's plush Melrose suburb on his way to dinner at a friend's house.
The blood-spattered body of the heavy-set businessman was found slumped over the steering wheel of his bullet-riddled car after it smashed into the railing of a bridge. Police said Mr Kebble was shot five times.
The murder attracted particular attention because of Mr Kebble's business and political connections.
"This chilling attack in our financial capital can only harm the reputation of South Africa as a place in which to do business," said Neal Froneman, the chief executive of mining giant Aflease Gold and Uranium Resources.
South Africa, the world's largest gold and platinum producer, has a high violent crime rate and Johannesburg has a reputation as the world's murder capital. Police hinted it was unlikely Mr Kebble was a victim of an ordinary carjacking. A police spokesman, Chris Wilken, said carjackers usually took the vehicle or some of the victim's belongings with them. "In this case, they didn't take anything."
The controversial white businessman, a lawyer by training, had recently had business troubles. Last month, he was ousted as chief executive officer of three major mining companies he founded amid allegations of multi-million dollar fraudulent dealings.
Mr Kebble was accused of having irregularly sold 14.4 million shares worth £130m without the permission of eitherdirectors or shareholders. The money realised from the sales has not been accounted for and police are still investigating.
In politics, Mr Kebble had bankrolled the ANC's powerful Youth League, which is fighting a running public battle with Mr Mbeki over Mr Zuma's sacking and other policy differences.
He reportedly was among the key benefactors of Mr Zuma, who was sacked by Mr Mbeki after a court ruled that he had received bribes. Mr Kebble had been helping to raise money for Mr Zuma's hefty legal bills.
The former attorney general Bulelani Ngcuka once accused the business magnate of giving financial support to the ANC Youth League for protection and political favours.
South Africa's anti-corruption unit, the Scorpions, arrested and charged Mr Kebble with fraud when Mr Ngcuka was still in office. The charges were dropped, but Mr Kebble said long declared that he would ask authorities to investigate Mr Ngcuka and the former Justice Minister Penuell Maduna for abuse of their public offices.
South Africa's respected Business Day newspaper said because of the "wealth that Mr Kebble was able to put at the disposal of key people" in Mr Mbeki's ruling ANC, his death would have a huge political impact.