Oscar Pistorius murder trial: Prosecution picks holes in athlete's testimony about fateful night when he killed Reeva Steenkamp

State prosecutor, Gerrie Nel, smiles while cross-examining South African Olympic and Paralympic sprinter Oscar Pistorius during his trial at the North Gauteng High Court (GETTY IMAGES)

Oscar Pistorius returned to the witness box for some ruthless questioning from state prosecutor, Gerrie Nel, who tried to pick holes in his version of events of the night he shot and killed Reeva Steenkamp through a locked toilet door.

On his third day of cross-examination, Mr Nel accused him of lying, tailoring his evidence and "getting deeper into trouble" in an effort to "cover up" lies. He signalled several contradictions in his testimony. Pistorius said he was tired but insisted proceedings should continue.

1. Asked by Mr Nel about whether he had turned the alarm on or off the night he shot Reeva Steenkamp dead, Pistorius said he "must have" turned it off, but the prosecutor claimed the answer was vague. The athlete said he didn't have an independent recollection of switching the alarm off. Mr Nel said he was not convinced.

2. Answering questions on whether he had been exposed to crime before the night of the shooting, Pistorius claimed he was followed by a black Mercedes on a highway and saw a muzzle flash followed by a bang noise some time in 2008/09. Fearing for his safety, he took the next turn and drove off to a shopping centre so someone could pick him up. He could not remember the person he phoned for help or how he got back home.

Mr Nel claimed that was improbable, before adding: "You remember exactly where you turned left, where you turned right, but you don't remember who you called. You don't want anyone to check up on it."

3. After saying he heard the noise of what sounded like an intruder kicking the toilet door, he then claimed he had "never" said someone kicked the door down, insisting he heard the noise of "wood" moving.

Pointing out a new mistake, Mr Nel told the court, addressing the athlete: "You are thinking of something that never happened and you have to keep up with an untruth".

READ MORE: CRIME SCENE PHOTOGRAPHS REVEAL BRUTAL SHOOTING

4. Earlier, Mr Nel noted that Reeva Steenkamp's jeans were found "laying on the duvet" on the floor next to a large tripod fan blocking his way en route to the balcony.

Pistorius has been adamant that the crime scene was contaminated by the police and objects were moved from where he left them, so the police photographs can't be trusted.

But Mr Nel insisted that, for Pistorius's version of events to be true, "police must have opened the curtains wider, moved the fans, switched the light on, put the duvet on the floor, and ensure the denim is on top of the duvet".

His defence counsel, Barry Roux, objected to his claim signalling that photographs taken from a different angle suggest otherwise.

Large fan and duvet would have blocked Pistorius's way en route to the balcony where he claims he called for help the night Reeva Steenkamp died. His defence claims the crime scene was contaminated and objects moved.

Yesterday, Mr Nel insisted that "nothing" was moved in the room and pointed out to a large fan next to the balcony door, which would have blocked his way as he tried to call for help after shooting Ms Steenkamp.

The position of the large tripod fan appears to contradict his version of events and would have made it difficult for him to reach the balcony.

"Let's sum up: A policeman moved the two fans, put the duvet on the floor, opened the curtains wider than they should be before the photographs were taken," Mr Nel told the court on Thursday, launching his case.

5. Pistorius insists Ms Steenkamp didn't scream after he shot the first out of four bullets through a locked toilet door, three of which hit her in the arm, hip and head. Today, Mr Nel told the court Pistorius previously admitted he could not hear "his own screams" because his ears "were ringing" after the first shot.

In a tense exchange, Pistorius conceded: "My Lady, the sound of that gunshot in the bathroom, you wouldn't have heard anyone scream.

"The decibels of the gunshot, I don't believe you would have heard anyone scream. When I had finished firing the gunshots, I was screaming and I couldn't hear my own voice."

Pistorius denies murdering Ms Steenkamp in the early hours of 14 February, claiming he shot her in a case of mistaken identity thinking she was an intruder. The state argues he intentionally shot and killed her following a domestic dispute.

The case continues.