PRETORIA (REUTERS/AFP) - South African prosecutors on Wednesday won their bid to appeal the culpable homicide conviction handed down to Olympic and Paralympic athlete Oscar Pistorius for killing his girlfriend and will now seek a murder conviction.

"I cannot say the prospect of success at the Supreme Court is remote," said Pretoria High Court Judge Thokozile Masipa in granting the appeal.

Judge Masipa denied the prosecutor Gerrie Nel's application to appeal Pistorius's five-year jail sentence and said the Supreme Court of Appeal should decide whether her acquittal of Pistorius on the charge of murder was correct, Bloomberg reported.

"Our argument was that he should have been convicted of murder, and then would have been sentenced to a minimum sentence of 15 years. That is of course what we would like to happen," said the National Prosecuting Authority's Nathi Ncube.

Pistorius, 28, was cleared of murder charges in September for the fatal shooting killing of his girlfriend, 29-year-old model and law graduate Reeva Steenkamp, at his upscale home in Pretoria on Valentine's Day last year.

Pistorius maintained throughout his seven-month trial that he shot Steenkamp on Feb 14, 2013, by mistake, thinking she was an intruder hiding behind the bathroom door in his house.

But the prosecution failed to convince Judge Masipa of Pistorius' intent to kill when he fired at his girlfriend, leading to his conviction in October for negligent killing - culpable homicide - and a five-year jail term. This meant that the Pistorius could end up spending only 10 months of his jail term at Pretoria's central prison.

In South African law, the judge who handed down a verdict decides on whether the judgement can be appealed.