Former Paralympian Oscar Pistorius has filed papers to the Constitutional Court appealing his 13-year sentence for murder.
The papers were filed on Monday, News24 has learnt.
Last month the Supreme Court of Appeal (SCA) in Bloemfontein increased his sentence to 13 years and five months in prison for the 2013 murder of his girlfriend Reeva Steenkamp.
The court said Pistorius should have been sentenced to 15 years, but the SCA took into account the time he had already served.
The State had applied to have Pistorius's initial six-year prison sentence increased.
The world-renowned athlete was arrested on Valentine's Day in 2013 – the day of the killing.
He fired four shots through a bathroom door, claiming that he believed there was an intruder in the bathroom.
North Gauteng High Court Judge Thokozile Masipa initially sentenced Pistorius to five years for culpable homicide in 2014.
Pistorius served only 10 months of the five-year sentence in prison before being released and put under house arrest.
The State appealed the culpable homicide conviction, and it was later replaced with murder by the Supreme Court of Appeal in 2016.
Masipa handed down a six-year jail term for murder.
The State petitioned the SCA directly, arguing that the six-year sentence was far too lenient.