Xolile Mngeni has a brain tumour, which has delayed the trial’s start, but a medical exam had found it would “not alter the situation in so far as the ability of the accused to understand” the proceedings, said Judge Robert Henney.
“We will proceed with this trial on Wednesday,” he said.
Mngeni was named as the gunman by his fellow accused Mziwamadoda Qwabe last week who pleaded guilty to the 2010 murder, which he said the pair had been recruited to carry out as a botched hijacking for her husband Shrien Dewani.
Qwabe said Mngeni, who arrived in court with a walking frame, had fired the shot from the front passenger seat and that they had agreed to a 15,000 rand ($1,800) fee. Qwabe was jailed for 25 years after his guilty plea.
It was the second plea bargain to implicate Shrien Dewani, whom South African prosecutors are fighting to extradite from Britain to stand trial.
In 2010, the driver entered his own plea and turned state witness and is serving 18 years in prison.
Britain has approved Dewani’s extradition but on March 30 the London High Court temporarily halted the process, citing mental health grounds. The businessman has strongly denied any involvement in the killing.