South Africa's ex-Olympic runner Oscar Pistorius will be released from prison on parole Friday, almost 11 years after he shot dead his girlfriend Reeva Steenkamp in a crime that gripped the world.

Having served more than half his sentence, the 37-year-old double-amputee will leave the Atteridgeville prison on the outskirts of the capital Pretoria.

The time and logistical details have not been disclosed by authorities, citing "security" reasons.

Pistorius, known worldwide as "Blade Runner" for his carbon-fibre prosthetics, will not be allowed to speak to the media as a condition of his parole.

Prison authorities have warned the press that there will be no opportunity to photograph him.

Pistorius killed Steenkamp, a model who was 29 years old at the time, in the early hours of Valentine's Day 2013, firing four times through the bathroom door of his ultra-secure Pretoria house.

The shooting came a year after Pistorius made history by being the first double-amputee to race at Olympic level when he appeared at the London 2012 games.

He was found guilty of murder and given a 13-year jail sentence in 2017 after a lengthy trial and several appeals.

He had pleaded not guilty and denied killing Steenkamp in a rage, saying he mistook her for a burglar. 

Steenkamp's mother has said she did not believe he had told the truth about what happened.

"My dear child screamed for her life loud enough for the neighbours to hear her. I do not know what gave rise to his choice to shoot through a closed door," June Steenkamp had said in her submission to the parole board.

Offenders in South Africa are automatically eligible for parole consideration after serving half of their sentence.

Pistorius lost a first bid in March when the board found he had not completed the minimum detention period required to be let out.

The Constitutional Court in October ruled that was a mistake, paving the way for a November hearing that approved his release.

As part of his parole, until the end of his sentence in 2029, Pistorius must undergo therapy for anger and gender-based violence issues.

He will also be banned from consuming alcohol and other substances, required to complete community service and also be home at certain hours of the day.

While June Steenkamp did not oppose parole for Pistorius and was "satisfied" with the terms, she was not convinced he was fully rehabilitated, a family spokesman has said.

"Nobody can claim to have remorse if they're not able to engage fully with the truth," she said in a statement.