A weeping Oscar Pistorius shielded his ears as a witness in his murder trial gave harrowing evidence about desperate attempts to save Reeva Steenkamp’s life after she was shot.

Rocking back and forth in the dock, Pistorius put his hands over his ears as neighbour and radiologist Johan Stipp on Thursday recounted how he entered his house to find the distraught Paralympian bent over, attempting to resuscitate his girlfriend.

Stipp noticed a wound on Steenkamp’s right thigh, right upper arm, and “blood, hair and what looked like brain tissue intermingled with that” on top of the skull and quickly realised the 29-year-old model’s injuries were too severe to be survivable.

“She had no pulse in her neck, she had no peripheral pulse, she had no breathing movements that she made. She was clenching down on Oscar’s fingers as he was trying to open her airway.”

“I opened her right eyelid, the pupil was fixed dilated and the cornea was milky, in other words it was already drying out, so to me it was obvious that she was mortally wounded.”

During the testimony, sobbing could be heard around the courtroom as Steenkamp’s family and friends sat arm in arm, disconsolate.

Stipp’s evidence is the first eye-witness account of what happened inside Pistorius’s home that evening since the trial began on Monday.

Pistorius stands accused of murdering Steenkamp, a 29-year-old model and law graduate.

He claims to have shot her through a locked toilet door after mistaking her for an intruder.

Stipp testified to being woken by gunshots and screams coming from Pistorius’s home on the night of February 14, 2013, and then rushing over to see if he could help, but the sequence of events appeared not to tally exactly with the evidence from three other neighbours who heard screams then shots.

Pistorius’s defence lawyer earlier accused one of those witnesses of tailoring his evidence to fit his wife’s account in order to “incriminate” the athlete.

Advocate Barry Roux contends the married couple’s testimony has “striking similarities” and is therefore contaminated.

The allegation could lessen the impact of the pair’s statements.