Paralympic gold medallist Oscar Pistorius faces a jail term of at least 15 years for killing his girlfriend on Valentine's Day 2013 after a court upheld an appeal that a lower court was wrong to find him guilty of culpable homicide, rather than murder.

Last year a judge gave Pistorius a five-year jail sentence for the "culpable homicide" of Reeva Steenkamp, but prosecutors appealed, saying he should be convicted of murder for firing four shots through a locked toilet door.

The Appeal Court said Pistorius could have foreseen the consequences of his actions when he fired four shots through the door in an extremely narrow place.

Describing evidence by Pistorius as 'confused and contradictory' the court said he had gambled with that person's life. "The identity of his victim is irrelevant to his guilt," the court said.

It dismissed pleas of self-defence, saying Pistorius never saw the person who he claimed to be a danger to him, and he did not even fire a warning shot.

He had no rational and genuine fear that his life was in danger," the court said.

Pistorius was recently released from prison and confined to house arrest. He will now be taken back to prison and await a fresh sentence. The minimum sentence for murder is 15 years.