A South African judge is expected to issue a ruling on Wednesday to decide whether or not prosecutors can appeal the sentence and conviction handed to Oscar Pistorius, who was sentenced to five years in prison for killing his girlfriend.

During the trial, the Paralympic athlete, also known as the "Blade Runner," argued that he shot Reeva Steenkamp on Feb. 14, 2013 by mistake because he thought she was a home intruder.

In September, Judge Thokozile Masipa acquitted him of murder charges, but found him guilty of culpable homicide--a lesser charge that is comparable to manslaughter. She then sentenced the double-amputee runner to five years at Pretoria's Central Prison, but he is only required to serve 10 months behind bars before he can be moved to community supervision or house arrest.

Prosecutors condemned the judge's verdict as too lenient and "shockingly light," and have filed an appeal.

"I say with utmost respect, too much mercy is shown. Perhaps the element of mercy was over-exaggerated," Chief prosecutor Gerrie Nel said to the court on Tuesday, according to the Associated Press.

"We are appealing the acquittal on the conviction of murder," Nel said, adding that the court had not taken all circumstantial evidence into account when it sentenced the 28-year-old athlete.

Nel said the court needs to consider that another court could may come to a different conclusion and, therefore, it must allow for an appeal.

Pistorius' lawyers, on the other hand, opposed the appeal request and said the sentence was not light.

"It's incorrect to say it's a light sentence. It's not," said defense lawyer Barry Roux, reports BBC News.

Addressing the judge, he added that the state can only appeal on matters of law, and not of fact.

"Their problem is they don't like your factual finding. They don't appreciate that. You absolutely, correctly applied the law," he said,

If the court does not grant prosecutors an appeal, then they will be free to petition the Supreme Court of Appeals to hear their case.