Oscar Pistorius' father, brother and sister were among members of his family in court for the start of his bail hearing on Tuesday (February 19).

In opening statements, the prosecution claimed that Pistorius put on his artificial legs and walked across his bedroom before firing four handgun rounds into the locked bathroom door, killing Steenkamp in cold blood.

The law graduate and model died after being hit by three rounds, prosecutor Gerrie Nel said.

Pistorius wept uncontrollably in court as Nel outlined details of the shooting in the early hours of Thursday.

Defence lawyer Barry Roux disputed the murder charge, saying the facts surrounding the shooting were unclear.

"All we really know is she locked herself behind the toilet door and she was shot," he told the packed Pretoria courtroom.

However, Nel, his counterpart at the bail hearing, painted a picture of premeditated killing - a crime that carries a life sentence in South Africa.

"If I arm myself, walk a distance and murder a person, that is premeditated," he said. "The door is closed. There is no doubt. I walk seven metres and I kill."