He said the decision by the parole board to free the athlete after serving 10 months of his five-year sentence was premature and without legal basis.
It could now take months for the board to review its decision, legal sources told the BBC.
Pistorius was convicted of manslaughter last year after shooting dead his girlfriend Reeva Steenkamp.
The Olympic athlete insists he mistook her for an intruder. He was due to be transferred from prison to house arrest on Friday, when he was expected to stay at his uncle's three-story mansion in the capital, Pretoria.
Under South African law, Pistorius is eligible for release under "correctional supervision", having served a sixth of his sentence.
One of his relatives, who did not want to be named, told Reuters news agency they were "shocked and disappointed" at the news.