On Wednesday Justice Minister Michael Masutha blocked the proposed release on parole because the decision was made prematurely. Masutha objected to the parole being granted in June, only eight months into the five-year sentence and not the required ten months.

A statement from the Department of Justice and Correctional Services clarified Musutha's decision.

"The decision to release him on 21 August 2015 was made prematurely on 5 June 2015 when the offender was not eligible to be considered at all. One-sixth of a five-year sentence is 10 months, and at the time the decision was made, Mr Pistorius had served only eight months of his sentence," it said.

Justice ministry spokesman Mthunzi Mhaga said Thursday that a review board has up to four months to decide whether Oscar Pistorius will be released from prison into house arrest. Mhaga also stated that no response to the decision has been received from Pistorius' lawyers.

Pistorius shot and killed Reeva Steenkamp, a law graduate and model, through a bathroom door in the early hours of Valentine's Day in 2013. He admited that he did shoot his girlfriend but said he mistook her for an intruder.

He was convicted of culpable homicide, the equivalent of manslaughter in South Africa, in October 2014 after the judge said that the prosecution did not prove his intent to kill Steenkamp, necessary for a murder conviction in South Africa. The prosecution has appealed his conviction to the nation's supreme court.

Families react

Steenkamp family lawyer Tania Koen said Reeva's parents welcomed the decision, adding that they "have always had faith in the justice system."

Jacqui Mofokeng, a member of a women's advocacy group, said Thursday that Steenkamp's mother told her it was the "best day ever for Reeva" when the news broke. She would have turned 32 on Wednesday.

"They said it was a better birthday than last year," said Mofokeng, who also serves as spokeswoman for a provincial branch of the ruling African National Congress.

Pistorius' lawyers have not indicated if they will oppose the minister's decision.

"We accept the decision made by the minister of justice and are considering our options," Pistorius family spokesman Anneliese Burgess told AFP.

A country reacts

News of the decision not to release Pistorius was met with jubilation among women's groups in South Africa with the spokeswoman for the ANC reminding the country that August is celebrated there as women's month.

"The ANC Women's League remains convinced that Judge [Thokozile] Masipa handed down an erroneous judgment and an extremely lenient sentence to Pistorius, setting a bad precedent in cases involving gender-based violence, especially in instances where women die at the hands of their partners. It is our wish that Pistorius remains in custody until November when the supreme court of appeal will hear the appeal brought by the NPA [National Prosecuting Authority] against the judgment and the sentence," read the statement.

The sentiment was similar on social media with many South Africans wondering how someone can serve only ten months for killing another person.

Sean Bekker on the Facebook page for Times Live, a South African news site, was puzzled that the parole board did not know the law and questioned if there were other motives behind the board's decision.

"This whole case is a perfect example of the imbalance of justice in this country. If you have enough cash (or are the president or one of his buddies) you can beat the system," he wrote.

"I'd show mercy for fraudsters and thieves etc, before showing mercy to a murderer. Why must Oscar get special treatment?" asked Wilbur McCoy on the Facebook page of News24, another South African news site.

It is widely believed that Pistorius was going to serve out his parole at his uncle's mansion with minimal supervision. He has been serving his time inside a maximum security prison but is being housed in the hospital ward separate from the general population.