Oscar Pistorius
Former paralympian Oscar Pistorius makes final attempt to overturn his murder conviction.Alon Skuy/The Times/Gallo/Getty

Former paralympian Oscar Pistorius is making a final attempt to overturn his murder conviction as he applied to appeal to South Africa's Constitutional Court on 11 January. Pistorius remains on house arrest until his sentencing on 18 April for murdering his girlfriend Reeva Steenkamp.

A lawyer on Pistorius's legal team, Andrew Fawcett, told AFP: "We have lodged an application for leave to appeal to the Constitutional Court. The application has been served on the director of public prosecutions, and they will now indicate when they will be opposing the application and what the grounds of opposition will be."

South Africa's Bloemfontein Supreme Court in December 2015 ruled that Pistorius was guilty of shooting dead Steenkamp at his house in Pretoria on 14 February 2013. Reading the verdict on behalf of the five-judge panel, Justice Eric Leach called the case "a human tragedy of Shakespearean proportions."

According to Leach, Pistorius was found changing his account of what occurred on the night of the murder several times. "In order to disturb the natural inference that a person intends the probable consequences of his actions, the accused was required to establish at least a factual foundation for his alleged genuine belief of an imminent attack upon him. This the accused did not do," said Leach.

"Consequently, although frightened, the accused armed himself to shoot if there was someone in the bathroom and when there was, he did. In doing so he must have foreseen, and therefore did foresee that the person he was firing at behind the door might be fatally injured, yet he fired without having a rational or genuine fear that his life was in danger ... I have no doubt ... the accused must have foreseen and therefore did foresee that whoever was behind that door might die. The identity of his victim is irrelevant to his guilt."

Pistorius was originally sentenced to five years in jail by Pretoria High Court Judge Thokozile Masipafor over culpable homicide or manslaughter of Steenkamp. He was later released in October 2015 to serve the remainder of his sentence under house arrest. However, he was found guilty of murder after prosecutors appealed to have his manslaughter conviction upgraded to murder.

The 29-year-old now faces a minimum sentence of up to 15 years in April. Meanwhile, Steenkamp's mother, June, told an Australian television channel earlier: "He [Oscar Pistorius] killed her. He admits he killed her. She's dead. Why didn't he just let her walk away? Why?"