Oscar Pistorius walked into the dock for day one of his murder trial with the eyes of Reeva Steenkamp's relations fixed on him from only a few yards away.

The 27-year-old, wearing a dark suit, entered the North Gauteng High Court in Pretoria, avoiding eye contact and passing directly in front of June Steenkamp, who was seated in the front row of the public gallery.

Reeva Steenkamp's mother had arrived at the trial flanked by relations. Husband, Barry Steenkamp was absent following a stroke he suffered late last week.

Pistorius shot dead model and reality TV star Reeva at his luxury home on the outskirts of Pretoria on Valentine's Day, last year. He admits gunning down Steenkamp, but claims he thought she was an intruder.

The paralympian is also charged with having illegal ammunition at his home.

Pistorius, one of the world's most recognisable athletes, faces spending most of his life behind bars if convicted of premeditated murder.