He said the decision by the parole board to free the athlete last Friday, after serving 10 months of his five-year sentence was blocked by the justice minister on grounds of being premature and without legal basis.
A court convicted him of culpable homicide, or manslaughter, over the killing of his girlfriend in 2013.
The double-amputee shot Reeva Steenkamp through a locked bathroom door at his home in South Africa's capital, Pretoria, believing she was an intruder, he told his trial.
The prosecution has appealed against the ruling, saying he should be convicted of murder.
Pistorius' defence lawyers are to file court papers to oppose the appeal on 17 September, a day before the parole review board meets, South Africa's privately ownedeNCA news site reports.
"We do understand that the parole [review] board will be sitting on the 18th of September. The date has been set," a family spokesman was quoted.
Pistorius wants to serve the rest of his prison sentence under house arrest.
He was born without the fibulas in both of his legs, and had surgery to amputate both below the knee while still a baby.
He went on to become one of South Africa's best-known sports stars, and was the first amputee sprinter to compete against able-bodied athletes, at the 2012 London Olympics.
