Paralympic champion Oscar Pistorius on Monday made a last-ditch attempt with South Africa's top court to overturn his murder conviction for shooting dead his girlfriend Reeva Steenkamp in 2013.
He has been on bail awaiting a new sentence since December, when judges found him guilty of murder, overturning his earlier conviction on the lesser charge of culpable homicide.
The double-amputee killed Steenkamp, a model and law graduate, in the early hours of Valentine's Day, saying he mistook her for an intruder when he shot four times through the door of his bedroom toilet.
Under the new conviction for murder, Pistorius, 29, faces a minimum 15-year jail term that may be reduced due to time already spent in jail and the fact that he is a first-time offender.
"We have lodged an application for leave to appeal to the Constitutional Court," Andrew Fawcett, a lawyer on Pistorius's legal team, told AFP.
Pistorius was released from jail in October to live under house arrest at his uncle's property in Pretoria after serving one year of his five-year prison sentence for culpable homicide -- the equivalent of manslaughter.
But Supreme Court of Appeal (SCA) judges last month described his testimony at his trial in 2014 as "untruthful" and delivered a damning indictment of the original verdict.
Legal papers filed at the Constitutional Court on Monday by Pistorius's lawyers contended that the SCA had "acted unlawfully and unconstitutionally" by rejecting factual findings of the original verdict.
They also accused the SCA of making "errors of law" over the principle of "dolus eventualis" -- awareness of the likely outcome of an action -- which has been at the crux of the long-running case.
- Dramatic trial -
Pistorius was last seen in public at his bail hearing on December 8 in Pretoria High Court, after which he was fitted with an electronic monitoring tag.
Under his bail conditions, he is allowed to leave his uncle's house at set times with official permission, and not travel further than 20 kilometres (12 miles).
"The application has been served on the director of public prosecutions," Fawcett said.
"They will now indicate when they will be opposing the application and what the grounds of opposition will be.
"Then we wait for the Constitutional Court to make a ruling on whether or not they will hear the appeal."
Pistorius denied killing Steenkamp in a rage and, during his dramatic trial, sobbed and occasionally vomited in the dock as details of his lover's death were examined in excruciating detail.
Some legal experts have dismissed his chances of success at the Constitutional Court.
"He is wasting his time. It is certainly not a constitutional matter," Tyrone Maseko, a Johannesburg attorney told AFP. "If he ever succeeds, then I will know there is no justice in this country."
Pistorius shot Steenkamp at the peak of his fame, and has since lost his glittering sports career, lucrative contracts and status as a global role model for the disabled.
Her family welcomed his murder conviction and has described his Constitutional Court appeal as a "delaying tactic" to keep him out of jail.
"The Steenkamps have faith in the justice system and the law must take its course," their family lawyer Tania Koen told AFP on Monday.