Giving evidence for a second day, sports medicine Professor Wayne Derman said the Paralympic athlete had developed an "exaggerated fight response" and suffered "significant stress and anxiety".

Derman, who treated Pistorius for six years, said this was responsible for the "horrific tragedy".

Describing how Pistorius' disability had affected his life, Derman said the athlete had lived with a "lifetime of real and learnt vulnerability".

The athlete's lower legs were amputated when he was a baby becuse he was born without fibula bones.

Arnold, Oscar Pistorius' uncle, helps the Paralympic athlete with his tie during today's proceedings in court ©Getty Images



Derman is the final witness being called by the defence in the trial in Pretoria.

Pistorius denies deliberately killing his girlfriend Reeva Steenkamp on February 14 last year, claiming he fired four shots through a toilet door - three of which struck the 29-year-old model - because he thought there was an intruder.

Under cross-examination, the prosecution claimed Derman's evidence could not be objective because of his relationship with Pistorius - something he denied.

On Monday, the court heard the result of a psychiatric report, which ruled the 27-year-old athlete was not mentally ill when he shot Steenkamp dead.

He had spent a month being assessed at the Weskoppies hospital in Pretoria ahead of the ruling.

The trial has been adjourned until Monday (July 7).