Oscar Pistorius was convicted of murder on Thursday by South Africa's Supreme Court of Appeal, which threw out his earlier conviction on a lesser charge for shooting dead his girlfriend in 2013.

Bloemfontein, South Africa: Oscar Pistorius was convicted of murder on Thursday by South Africa's Supreme Court of Appeal, which threw out his earlier conviction on a lesser charge for shooting dead his girlfriend in 2013.

Pistorius is now set to go back to jail after he was released on parole in October having served one year of his five-year sentence for culpable homicide - the equivalent of manslaughter.

"Guilty of murder, with the accused having criminal intent," judge Eric Leach told the court in a dramatic legal reversal.

"The matter is referred back to the trial court to consider an appropriate sentence."

The 29-year-old star Paralympic sprinter shot dead Reeva Steenkamp, a model and law graduate, in the early hours of Valentine's Day two years ago.

He said during his trial that he mistook her for an intruder when he opened fire at the locked door of his bedroom toilet.

"He did not know whether that person constituted any threat," Leach said in a damning rejection of the testimony from Pistorius and the original trial judge's ruling.

"It is inconceivable that a rational person thought he was entitled to fire at this person with a heavy-duty firearm," said Leach, who described Pistorius's testimony as "vacillating and untruthful".

"He must have foreseen that the person behind the door might be injured.

"He ought to have been convicted not of culpable homicide... but of culpable murder."

Pistorius, who was not be present in court in Bloemfontein, South Africa's judicial capital, now faces a minimum of 15 years in prison for murder.

Awaiting his new sentence, he is likely to remain under house arrest at his uncle's mansion in the capital Pretoria.

Dramatic trial

His trial attracted worldwide attention as he denied killing Steenkamp in a rage after the couple had gone to bed.

"I was overcome with fear," he said while in the dock, describing how he thought he heard an intruder in the bathroom.

He grabbed his gun, and rushed without his prostheses to the bathroom.

"Before I knew it, I'd fired four shots at the door," he said, adding that he ran back to the bed only to find that Steenkamp was not there.

Pistorius killed Steenkamp at the peak of his fame, following his historic performance in London in 2012 when he became the first double-amputee to race at Olympic level.

Last month he made his first appearance in public since leaving jail when he reported for community service at a police station in Pretoria.

A Pistorius family spokesman said no statement would be released after Thursday's verdict.

Steenkamp's mother June was in court, but made no immediate comment.

His parole conditions have not been made public, but are reported to require him to meet with Steenkamp's parents if they wish.

Pistorius may make his own appeal to South Africa's Constitutional Court - the country's highest court.

But defence lawyers say he cannot afford further legal battles, having already paid huge bills.

In the aftermath of the killing, the Paralympic gold medallist lost his glittering sports career, lucrative contracts and status as a global role model for the disabled.

AFP