Oscar Pistorius's defence lawyer Barry Roux has questioned the autopsy findings delivered by the pathologist that carried out the postmortem on Reeva Steenkamp.

The South African model was shot dead by her boyfriend Pistorius after 3am on Valentine's Day last year through a bathroom door at the Paralympian's home in Pretoria.

During the athlete's trial, Professor Gert Saayman told the High Court that the food contents in Steenkamp's stomach suggest that the model ate no more than two hours prior to her death.

However, Pistorius has claimed that the couple went to bed at around 10pm, which means that Saayman's evidence would indicate that Steenkamp must have eaten after 1am.

Pistorius's lawyer questioned the professor's methods and asked to be shown the medical tests that he took to come to the conclusion of when Steenkamp last ate.

The double amputee denies murder by maintaining that he mistook Steenkamp for an intruder when he fired the shots.