South Africa's state prosecutors say they will appeal against the conviction and sentence handed to Oscar Pistorius.
They say they are not happy with the five-year jail term that he was handed last Wednesday, or the manslaughter offence for which he was convicted.
National Prosecuting Authority spokesman Nathi Mncube said on his Twitter feed: "Oscar Pistorius judgement, NPA will be appealing both the conviction and sentence."
Mr Mncube said the next step was to file papers in court.
Pistorius started serving his prison sentence on October 21 after a seven-month trial.
Judge Thokozile Masipa acquitted him of murder and found him guilty of a lesser charge of culpable homicide, or manslaughter, for shooting his girlfriend Reeva Steenkamp through a toilet door in his home.
As things stand, the Olympic runner is eligible for release after 10 months so he can complete his sentence under house arrest.
Sentencing options available to the judge in a culpable homicide case included up to 15 years in jail, a suspended sentence, a correctional supervision or a fine.