Paralympic champion Oscar Pistorius has revealed that he was "scared" that an intruder had entered his home and was unaware that he had killed girlfriend Reeva Steenkamp when he opened fire, a court has heard.

The 26-year-old, who has been formally charged with the premeditated murder of the 29-year-old model at his home in Pretoria last week, has been accused of shooting Steenkamp dead through a bathroom door.

The defence have denied premeditated murder and have begun their application for bail at the hearing in South Africa today.

"I'm acutely aware of people gaining entries to homes to commit crime, I've received death threats," Pistorius's statement read by defence lawyer Barry Roux is quoted by Eyewitness News journalist Barry Bateman as saying. "I sleep with my 9mm under my bed. I woke up to close the sliding door and heard a noise in the bathroom.

"I was scared and didn't switch on the light. I got my gun and moved towards the bathroom. I screamed at the intruder. Because I did not have my legs on I felt vulnerable. I fired shots through the bathroom door and told Reeva to call police. I walked back to the bed and realised Reeva was not in bed. Its then it dawned on me it could be her in there.

"I kicked the door open, called paramedics and complex security. I tried to carry her down stairs for help. I tried to help her but she died in my arms. With the benefit of hindsight I realise that Reeva went to the bathroom when I went to close the balcony door. I am an international sports star, I will not evade my trial. After the shooting I did not flee the scene. I remained until the police arrived."

The schedule six offence indicates that Pistorius is unlikely to be granted bail.