The "emotionally drained" uncle of Oscar Pistorius has launched a stinging verbal attack on the prosecution led by Gerrie Nel.

Speaking after Oscar Pisorius was jailed for five years, Arnold Pistorius said Nel and his colleagues inflicted as much pain as possible during the seven-month-long trial.

Oscar, 27, lived with his uncle throughout proceedings, which were marked by the runner's emotional outbursts during tough cross-examination by Nel.

Arnold attended every day of the trial, in which his nephew's fall from grace was played out in minute detail and broadcast across the world.

Arnold also revealed the family does not intend to appeal the five year prison sentence handed to the fallen star for shooting dead his girlfriend Reeva Steenkamp in a volley of gunfire.

Describing the time since her death as "harrowing" and "incredibly hard", Pistorius senior said: "This has been an incredibly hard, painful process for everyone involved. It has been a harrowing 20 months, we are all emotionally drained and exhausted.

"The case, which was set down for three weeks originally, has been dragged out for seven months. We said from the beginning that the state tried to force a puzzle into a position of pre-meditated murder.

"When they realised the fact that it didn't fit, they changed their stance to a mosaic where everything can opportunistically fit everywhere. In the process they decided to inflict as much collateral damage as they could by keeping a cloud of pre-meditated murder over this case for as long as possible."

Oscar Pistorius was jailed for the culpable homicide offence and given a suspended sentence for two firearms charges.

But the ordeal for Pistorius and his family may yet not be over. The State prosecutor has indicated an appeal may follow against the culpable homicide verdict, in an attempt to raise it to murder.

Arnold Pistorius said his nephew, the fallen track idol, would treat imprisonment at Pretoria Central Prison as an "opportunity to pay back to society".

He insisted the family will support the Paralympian. "As an uncle, I want to say I hope Oscar will start on his healing process as he walks down the path of restoration. As a family we are ready to support and guide Oscar as he serves his sentence," said Arnold Pistorius.