Prosecutors appeal 'shockingly light' Pistorius verdict

South African prosecutors are appealing the verdict and sentence of Paralympian Oscar Pistorius, who was last month handed a five-year jail sentence for killing his girlfriend.

After a sensational eight-month trial, Pistorius was found guilty of culpable homicide, a charge equivalent to manslaughter, for shooting dead his model girlfriend Reeva Steenkamp on Valentine's Day 2013 and began to serve his sentence on October 21.

Prosecutors announced last week that they would press for a murder conviction and a harsher sentence and on Tuesday officially lodged the appeal.

"Today, we announce that the NPA filed the application for leave to appeal both the conviction and sentence," the National Prosecuting Authority said in a statement.

"The appeal on conviction is based on the question of law."

During his trial, Pistorius admitted to shooting Steenkamp, 29, four times through a locked toilet door at his upmarket Pretoria home, but said he thought he was firing at an intruder.

Prosecutors alleged that he had shot Steenkamp on purpose after the couple had argued.

High Court Judge Thokozile Masipa found there was not enough evidence to convict the 27-year-old Paralympic and Olympic athlete of premeditated murder.

The disgraced athlete is currently serving his sentence at a hospital section of a Pretoria prison.

The appeal sets the stage for another instalment of a legal battle that has gripped millions around the world.

The date for the appeal application has not been set.

The NPA spokesman Nathi Mncube said the application for permission to appeal was expected to be heard by the same judge, Masipa, at the High Court.

"After presenting our case, the judge will either grant or reject our application," said Mncube.

"If it's granted, the case will then be heard by the Supreme Court of Appeal."

Mncube stressed that in case Masipa did not grant the appeal, the state had an option to petition the Supreme Court to hear the case.

Cases heard by the Supreme Court, which is located in South Africa's central city of Bloemfontein, are presided by a panel of three to five judges, depending on the nature of a case.

Pistorius became famous as the first double amputee Paralympian to compete against able-bodied athletes at the 2012 London Olympics.

His imprisonment has curtailed his career, with the International Paralympic Committee banning him from competitions for five years.

Both Pistorius' and Steenkamp's families accepted the decision by the prosecutors to appeal when it was announced last week.

The Steenkamps have said they had no plans to pursue a civil case against the athlete.