Olympic athlete Oscar Pistorius has been found guilty of murder after a South African appeals court overturned an earlier manslaughter verdict.

He killed his girlfriend Reeva Steenkamp in February 2013 after shooting her four times through a locked door.

He is currently under house arrest after spending a year of his five-year sentence in jail for a crime of culpable homicide (manslaughter).

Prosecutors had appealed against the original verdict to try to achieve a murder conviction.

Pistorius will now have to return to court for a new sentence to be decided.

South Africa’s Supreme Court of Appeal ruled that the lower court did not correctly apply the rule of dolus eventualis – whether Pistorius knew that a death would be a likely result of his actions.

Reading the ruling reached by a panel of judges, Justice Lorimer Leach said that having armed himself with a high-calibre weapon, Pistorius must have foreseen that whoever was behind the door might die.

Justice Leach compared it to someone setting off a bomb in a public place not knowing who the victims might be.

He added that Pistorius did not take that most elementary precaution of firing a warning shot.

Pistorius’ lawyer argued that he believed that there was an intruder in the house but the judge said that the identity of the person behind the door was irrelevant.

The minimum sentence for murder is 15 years but judges can apply some discretion.