Oscar Pistorius's slain girlfriend is to be cremated Tuesday as the South African "Bladerunner" athlete appears in court for a bail hearing expected to reveal more about what happened the night she was shot dead.

Model Reeva Steenkamp, 29, was shot four times in the early hours of Thursday by a 9mm pistol owned by the sprinter, and she died of her wounds at the scene.

Pistorius's family has insisted that the evidence will refute "any possibility of a premeditated murder or indeed any murder at all".

Defence lawyers are expected to argue that there are "exceptional circumstances" for Olympic athlete Pistorius to be freed pending trial.

As a result, more details will likely emerge of what happened during the Valentine's Day shooting at Pistorius's upmarket home in a gated estate in the South African capital.

The state, arguing premeditated murder, will oppose bail.

Both sides have called in heavyweight lawyers, setting the scene for a massive legal showdown.

In Port Elizabeth meanwhile, Steenkamp's family were preparing their final farewells.

In an interview published on Monday, Steenkamp's mother described her death as "horrendous."

"Why my little girl? Why did this happen? Why did he do this?" June Steenkamp told the Times of South Africa.

"She had so much of herself to give and now all that is gone. Just like that, she is gone... In the blink of an eye and a single breath, the most beautiful person who ever lived is no longer here."

Her uncle said the family bore the runner no grudge but wanted clarity about Steenkamp's death.

"The family haven't got that animosity or hatred or anything like that but questions, and we realise that it's going to come out," Michael Steenkamp told AFP.

Steenkamp's parents were having a quiet day at home ahead of her memorial after the arrival of family members and friends.

Michael Steenkamp said the family were not watching television or listening to the radio. "We just ignore it completely."

On Saturday a celebrity television show aired haunting footage of Reeva Steenkamp speaking about the need to leave a positive mark on life, words laden with poignancy after her death.

"Not just your journey in life, but the way that you go out and make your exit is so important, you have either made an impact in a positive way or a negative way," she said.

The law graduate had been going out with the 26-year-old Pistorius since late last year.

Unconfirmed reports have suggested he mistook her for an intruder, while other reports said she was beaten with a cricket bat before being shot multiple times.

Pistorius, who broke down in sobs during his first court appearance on Friday, has built up a powerful team of lawyers, medical specialists and public relations experts for his defence.

Stuart Higgins, a former editor of British tabloid The Sun, whose lengthy list of clients includes British Airways, Chelsea FC and Manchester United football club, has taken over his public relations.

One of the lawyers, Kenny Oldwage, defended the driver in a 2010 accident that killed former president Nelson Mandela's great-grandchild Zenani. The driver was acquitted.

A global inspirational figure, Pistorius was the first double amputee to compete against able-bodied athletes in the 2012 London Olympic Games.

As testimony to his accolades, the north Gauteng Province athletics association named him male athlete of the year in track and field two days after the shooting.

The killing has put his career on hold, forcing him to cancel races in Australia, Brazil, Britain and the United States between March and May, his agent Peet van Zyl said.

Sponsors and partners will maintain their contractual commitments awaiting the outcome of the legal process, Van Zyl added.