Pretoria — Murder-accused Oscar Pistorius's defence may not consult State psychiatrist Carla Kotze, Judge Thokozile Masipa ruled on Monday.
"No basis has been laid for the request to consult Dr Kotze," Masipa said in the High Court in Pretoria.
"The defence is not permitted to consult with Dr Kotze."
Masipa said Kotze was not a "normal witness" and merely because she was in court did not mean Pistorius's defence could speak to her.
Pistorius is charged with murdering his girlfriend Reeva Steenkamp on Valentine's Day last year.
Barry Roux SC, for the athlete, said he had wanted to consult Kotze before deciding on calling a last witness.
Prosecutor Gerrie Nel objected, saying the defence could consult its own psychiatrist Dr Leon Fine.
Kotze and Fine were part of the panel of three psychiatrists and one clinical psychologist who observed Pistorius for 30 days at Weskoppies Psychiatric Hospital following a court order.
Masipa on Monday said she did not think allowing the defence to consult Kotze would be in the interest of justice.
Roux asked the court to adjourn to Tuesday, when the athlete's defence is expected to close its case.
Pistorius claims he shot Steenkamp by accident through the locked door of the toilet in his home, thinking she was an intruder about to emerge and attack him.
He broke the door down with a cricket bat to get to a dying Steenkamp. He has testified that he found her slumped over the toilet, picked her up and carried her downstairs.
The State contends he killed her during an argument.