South African prosecutors have filed an appeal calling for Paralympian Oscar Pistorius to be convicted of murder for killing his girlfriend Reeva Steenkamp.
Pistorius was jailed last year after being convicted on the lesser charge of manslaughter over the 2013 killing, and is due to be released from prison on Friday (local time).
"What I can assure you is that today the papers were filed in the Supreme Court of Appeal," said National Prosecuting Authority spokesman Luvuyo Mfaku on Monday.
Pistorius's defence team has until September 17 to file its response.
The appeal is expected to be heard in November.
Pistorius, who became a global hero after competing in both the Paralympics and Olympics, claimed he mistook Steenkamp for an intruder when he fired four shots through a locked bathroom door on Valentine's Day in 2013.
The 28-year-old athlete was acquitted on a charge of murder but found guilty of culpable homicide, a charge equivalent to manslaughter, and sentenced to five years in prison.
The state is appealing the judgment, arguing that Pistorius deliberately killed the 29-year-old model and law graduate after an argument.
Pistorius will leave prison this Friday after less than a year behind bars after the parole board agreed to place him under correctional supervision - a form of house arrest.
If the appeal court finds him guilty of murder, the athlete known as the "Blade Runner" for the prosthetic legs he wears on the track could face at least 15 years in jail.