Oscar Pistorius faces a return to prison after South Africa's Supreme Court of Appeal ruled his initial manslaughter conviction for killing girlfriend Reeva Steenkamp should be changed to murder.

Pistorius was handed a five-year jail term last October for the "culpable homicide" of Steenkamp, whom he killed by firing shots through a locked bathroom door on Valentine's Day 2013.

The Paralympic gold medallist, who said he thought Steenkamp was an intruder, was released and put under house arrest this October, having served a fifth of his sentence.

However, prosecutors said Pistorius should have been charged with murder – arguing the application of the law in his trial was not correct - and the Supreme Court of Appeal ruled in their favour on Thursday.