Oscar Pistorius enters the dock before in court proceedings at the Pretoria Magistrates court, June 4, 2013. [Photo/Agencies]

In a statement, the National Prosecuting Authority said that it would be "inappropriate" to comment about "the charges" before they were presented in court. The language of the statement, using the plural charges, suggested that more could be added.

Pistorius' legal team also would not comment in detail on the charge or charges but a spokeswoman said his defense lawyers expect to see a copy of the indictment papers before Monday so they can prepare. The lawyers were locked in meetings on Friday, the spokeswoman, Anneliese Burgess, said.

Those indictment papers would also include additional information like a witness list and some details of the evidence police have gathered in the half a year since Pistorius fired four bullets from his licensed 9mm gun through the locked toilet door in the pre-dawn hours, hitting Steenkamp in the head, elbow and hip. One bullet missed her and was recovered from the toilet bowl.

Pistorius was initially charged with premeditated murder for bail purposes while police investigated the circumstances of the shooting, which has gripped millions and shone a spotlight on Pistorius' life.

The world's best-known disabled sportsman once inspired many by overcoming the adversity of losing his lower legs as a baby to win the right to compete against able-bodied athletes and qualifying to run at the biggest sports event of all, the Olympics.

Last Monday, photographs were published of Pistorius paddling in a kayak on a beach holiday with friends and standing on the sand, his pale prosthetic legs exposed in shorts in a rare public appearance.

This year's Paralympic and able-bodied world championships have flashed by without him, with Pistorius yet to run competitively anywhere since the killing and only using the sport that made him a huge star to help his mental state.

"Those close to him have encouraged him to spend a few hours a week on the track to assist him in finding the necessary mental and emotional equilibrium to process his trauma and prepare for the trial," Pistorius' family said in their last public statement.