Bloemfontein – Former Paralympian Oscar Pistorius, convicted of the 2013 murder of his girlfriend Reeva Steenkamp, is expected to know on Friday whether he must serve more time behind bars.

The Supreme Court of Appeal (SCA) in Bloemfontein is ready to deliver its verdict in an appeal the State had lodged to have his initial six-year prison sentence increased.

The world-renowned athlete was arrested on Valentine’s Day in 2013 – the day of the killing.

He claimed that he had mistaken Steenkamp for an intruder.

Judge Thokozile Masipa later sentenced him in the North Gauteng High Court in Pretoria.

'Sentence should reflect gravity of crime'

During arguments in the appeal, the court heard that Judge Masipa failed to put forward substantial and compelling reasons for deviating from the minimum sentence of 15 years.

Prosecutor Andrea Johnson told the court the judge erred in her judgment and in sentencing Pistorius to six years.

"The sentence should reflect the gravity of the crime," she said at the time.

"The court regarded Pistorius' belief that there was an intruder in the house as a mitigating factor," Johnson said of the previous judgment.

During the trial, Pistorius maintained that he had no intention of murdering his girlfriend.

When he testified, he became emotional and apologised to the Steenkamp family.