JOHANNESBURG, April 9 (Xinhua) -- Oscar Pistorius, former South African Paralympic athlete, suffered a heavy blow on Monday after his request was dismissed to appeal against his 13-year jail term, the National Prosecuting Authority (NPA) said.

Pistorius had asked the Constitutional Court to review the jail term, which was increased to 13 years in November.

"The application for leave to appeal is dismissed," a South African court ruled on Monday, adding it was not a constitutional matter.

The ruling was dated March 28.

"I don't foresee any other option for Oscar, this is the end of the road for Mr Pistorius," NPA spokesperson Luvuyo Mfaku told Xinhua on Monday.

"We received an order from the ConCourt that specifically says that his application for leave to appeal has been dismissed due to the fact that it does not fall within the jurisdiction of the ConCourt," he added.

Pistorius killed his girlfriend, Reeva Steenkamp on Valentine's Day in 2013. He fired four times through the locked door of his bedroom toilet, later saying that he thought she was an intruder.

According to Tania Koen, the Steenkamp's family lawyer, Reeva's parents had "always had faith in the justice system of the country."

"June and Barry have been focusing their time and energy in the Reeva Rebecca Steenkamp Foundation which was established in her memory," Koen told the media.

He was convicted of culpable homicide in 2014, but his conviction was upgraded to murder on appeal.

Pistorius's legal team and state prosecutors have been battling through the courts over the length of his sentence.

Before he murdered his girlfriend, Pistorius became the first double-amputee to race at the Olympics when he competed at the London 2012 games.