The 27-year-old is accused of murdering the South African model, whom he shot dead through a bathroom door at his home in the early hours of Valentine's Day last year.
On day three of Pistorius's testimony, the double amputee told the court his account of what occurred after he realised that he had shot Steenkamp through the toilet door close to his bedroom.
Pistorius claimed that he called the emergency services and 'screamed' for neighbours to help before realising that his girlfriend was dead. He told the court: "Reeva had already died while I was holding her, before the ambulance arrived, so I knew there was nothing more I could do for her."
Pistorius, who had to stop on occasion to compose himself while speaking at the witness stand, was asked whether he intended to murder his girlfriend, to which he replied: "I did not intend to kill Reeva, m'lady, or anyone else for that matter."
The athlete denies the charge by maintaining that he mistook Steenkamp for an intruder when he fired the shots.