Oscar Pistorius
Olympic and Paralympic track star Oscar Pistorius reacts as Judge Thokozile Masipa (unseen) delivers her verdict at the North Gauteng High Court in Pretoria Sept. 12, 2014. Reuters/Alon Skuy/Pool

Oscar Pistorius’ defense lawyers failed to prevent prosecutors from appealing the double-amputee’s culpable homicide verdict in the killing of his girlfriend Reeva Steenkamp. South African Judge Thokozile Masipa ruled in the Johannesburg High Court on Friday that the application be dismissed.

In December, Masipa had granted permission to prosecutors to take the case to South Africa's Supreme Court of Appeal and challenge her ruling. Prosecutors had sought the more serious charge of premeditated murder against Pistorius for fatally shooting Steenkamp through a locked bathroom door at his home on Valentine’s Day in 2013. But, in September, the judge had ruled Pistorius not guilty of premeditated murder, and convicted him of culpable homicide and subsequently sentenced him to five years in prison.

"In my view, to entertain this application will be tantamount to reviewing my own decision," Masipa reportedly said. “For one thing there is really nothing new in the submissions by council for the applicant," she said in her ruling on Friday.

The 28-year-old could be eligible for release in August -- 10 months after his sentencing -- and serve the remainder of his sentence under house arrest. However, if the prosecutors succeed in their appeal, Pistorius could face a sentence of at least 15 years in prison.

Meanwhile, the Guardian reported of a controversy over “privileges” allegedly granted to the former Olympian inside Pretoria's Kgosi Mampuru II prison, where he is serving out his sentence. And earlier this week, South Africa’s Daily Sun published footage of Pistorius playing football in a prison yard with Radovan Krejcir, a Czech prisoner facing kidnapping, attempted murder and drug-dealing charges.