A ballistics expert testifying for Oscar Pistorius’ defence says the bullets that hit Reeva Steenkamp were not in the order prosecutors claim, offering key evidence in the star’s murder trial.

Tom ‘Wollie’ Wolmarans sought to show the sequence of the bullets showed Steenkamp was reaching for the toilet door and not putting her hands to her face defensively.

The model’s final movements have been used by the defence to show Pistorius shot the 29-year-old mistaking her for an intruder, while the prosecution has sought to show he knew she was in the cubicle and wilfully fired.

Wolmarans told the court Steenkamp was close to the toilet door and leaning slightly forward when the first of four gunshots hit her hip.

The next bullets hit her arm and hand, and the final bullet hit her head as she fell backward.

Wolmarans’ testimony runs in the face of police ballistics testimony, which said one bullet missed and ricocheted off the wall, injuring Steenkamp’s back and the final bullet hit her hand and head as she was sitting in a defensive position with her hands over her head.

The defence witness said all four hollow-point bullets hit the 29-year-old model and law graduate, and the same bullet could not have hit both her hand and head; otherwise, there would be brain tissue found on her hand.

He said the back wounds were “consistent with falling off a blunt surface” and caused when Steenkamp fell on a wooden magazine rack in the toilet.

The state’s version, that Steenkamp fell into a seated position on the magazine rack, “doesn’t make sense to me”, Wolmarans said.

The expert testimony bolsters the defence claim Steenkamp was reaching for the toilet door handle when she was shot by Pistorius.

The Paralympic gold medallist claims he shot his girlfriend by accident, believing her to be an intruder in his upmarket Pretoria home.

In contrast, the state claims 27-year-old Pistorius shot Steenkamp in a fit of rage following an argument. If found guilty of premeditated murder, the double-amputee faces up to 25 years to life in prison.

Pistorius began the day in good spirits, cracking a rare smile in court as he greeted Wolmarans, a former policeman with more than 30 years’ experience in ballistics.