PRETORIA, South Africa - The judge overseeing the murder trial of Oscar Pistorius on Wednesday ordered the double-amputee athlete to undergo psychiatric tests, meaning that the trial proceedings will be delayed.

Oscar Pistorius looks on during his trial at the North Gauteng High Court in Pretoria, May 13, 2014. The Olympic and Paralympic track star is standing in the Pretoria dock to face a charge of murdering his girlfriend Reeva Steenkamp on Valentines Day 2013. [Photo/Agencies]

The decision by Judge Thokozile Masipa followed a request for a psychiatric evaluation by the chief prosecutor, Gerrie Nel. The prosecutor had said he had no option but to ask for it after an expert witness for the defense testified that Pistorius had an anxiety disorder that may have influenced his judgment when he fatally shot his girlfriend, Reeva Steenkamp.

Masipa said the court was ``ill-equipped'' to assess the diagnosis by Dr. Merryll Vorster, and should therefore send Pistorius for a period of evaluation. She said it was important to assess the Olympic runner's state of mind because of questions raised by the prosecution that Pistorius might argue he was not criminally responsible because of his anxiety disorder.

``The accused may not have raised the issue that he was not criminally responsible at the time of the incident in so many words, but evidence led on his behalf clearly raised the issue and cannot be ignored,'' the judge said.

Masipa noted that having Pistorius evaluated as an outpatient would be preferable as the referral for psychiatric analysis was not meant to punish him, and acknowledged that trial proceedings would be delayed for an unspecified amount of time.

``This is not about anyone's convenience, but rather about whether justice has been served,'' said Masipa, adding that she would provide details about her decision in court on Tuesday.

Nel, the prosecutor, had previously referred to a period of 30 days for a psychiatric evaluation. Any panel of experts that assesses Pistorius would likely take additional time to compile a report and submit it to the court. The trial started March 3.

Pistorius says he killed Steenkamp on Feb. 14, 2013 by mistake, thinking there was an intruder in his home. The prosecution says the Olympic runner killed her after an argument.