The judge last month acquitted the double amputee sprinter of the more serious charge of murder over Reeva Steenkamp's death.

But she found him guilty of culpable homicide, for which the punishment could range from a fine to up to 10 years jail time.

In her judgement Judge Masipa dismissed both submissions that suggested Mr Pistorius serve home detention before handing down her sentence of a five year jail term for culpable homicide.

"Considering the degree of negligence - the house arrest sentence would not be appropriate." 

On a second charge of violating the firearms act, Judge Masipa sentenced Pistorius to three years, wholly suspended.

Judge Masipa said she had no reason to believe Mr Pistorius' disability would present a problem to him being imprisoned.

"I have no reason to believe the accused would present Correctional Services with an insurmountable challenge.

She said that his firearm was an area of consideration when handing down the sentence however, accepted Mr Pistorius' remorse and his efforts to reach out to Steenkamp's family. 

"The accused had been trained in the use of and handling of firearms. In my view, that is very aggravating," she said. 

Judge Masipa said while the loss of life cannot be reversed she hoped the sentence could provide closure for the family and all concerned.

It has been reported that Mr Pistorius will not appeal his sentence.

The Steenkamp attorney said the decision was a "very well considered sentence" and Reeva's Steenkamp's family appeared satisfied with Judge Masipa's decision.

Oscar Pistorius has been found not guilty of murdering his girlfriend Reeva Steenkamp by South African Judge Thokozile Masipa after she found the prosecution had failed to prove that Mr Pistorius had killed Ms Steenkamp with premeditation. 

"The state has not proved beyond reasonable doubt that the accused is guilty of premeditated murder," she said. "There are just not enough facts to support such a finding."

She also said that because Mr Pistorius believed his life was in danger he therefore could not be found guilty of a lesser charge of murder.

"How could the accused reasonably have foreseen that the shot he fired would kill the deceased?" Judge Masipa said.

"Clearly he did not subjectively foresee this as a possibility, that he would kill the person behind the door, let alone the deceased as he thought she was in the bedroom at the time."

Mr Pistorius admitted shooting Ms Steenkamp dead on Valentine's Day (February 14) last year but, claims he was trying to protect himself and his girlfriend from a dangerous intruder and pleaded not guilty to the charge of premeditated murder.

During a second and final day of closing arguments, the defence said Pistorius feared there was an intruder and was "startled" when he fired four shots at his toilet door on Valentine's Day last year, killing Reeva Steenkamp.

Barry Roux, the chief defence lawyer, told Pretoria's High Court that the 27-year-old double-amputee had a heightened "fight response" because of his disability, citing a "primal instinct" that led him to pull the trigger.

In a fiery final defence of his client, Mr Roux, his voice rising in intensity as the trial neared its end, took the court back to the moment before Pistorius fired the gun in an attempt to prove that he had no intent to kill.

"It comes down to that split second in the accused's life, when he was standing at the entrance to the bathroom, firearm pointed at the door," he said. "That is what this case is about."

Throughout the trial, the defence sought to portray Pistorius as a vulnerable man obsessed with safety in a country with a high crime rate.

Mr Roux asked Judge Thokozile Masipa to consider the psychological effects of a lifetime of insecurities caused by Pistorius' disability, comparing his anxiety the night he shot 29-year-old Ms Steenkamp to that of a woman who snaps and kills her partner after years of abuse.

Pistorius faces at least 25 years in jail if convicted of premeditated murder. If found not guilty he could still face jail time on the charge of manslaughter, known as culpable homicide in South Africa. He also faces three gun charges.

"You have the effect of the slow burn of insecurities over many years. You're an athlete. You're trained to react to a sound, and he stands there now with his finger ready to fire, and then," Mr Roux said, before banging the wooden lectern in front of him.

Mr Roux admitted that Pistorius had been argumentative on the witness stand, but said that the facts of the case showed he had no intention of shooting Ms Steenkamp.

Gerrie Nel, the prosecutor, who delivered his closing argument on Thursday, had a final chance to speak at the end of the trial, saying that Pistorius must at the very least be found guilty of culpable homicide. "The accused intended to kill a human being," he said. "He knew there was a human being in that toilet."

In an about-turn, Mr Roux said in his closing argument that Pistorius was guilty of negligence for discharging a gun in a crowded Johannesburg restaurant, an incident that happened a month before Ms Steenkamp's death. He had previously pleaded not guilty to the charge.

In a tweet posted after leaving court, Pistorius thanked his family for their support, saying: "Thank you to my loved ones and those that have been there for me, who have picked me up and helped me through everything."

Born Oscar Leonard Carl Pistorius in 1986, the athlete had both legs amputated below the knee when he was 11 months old.  He began running on prosthetics at the age of 16, and won gold at the 2004 Athens Paralympics.

In 2012 he became the first amputee to compete against able-bodied athletes, in the London Olympic Games.  

Reeva Steenkamp was born in Cape Town in 1983 and grew up in Port Elizabeth. She began modelling in her teens and graduated with a law degree from Nelson Mandela Metropolitan University in 2005.

Twice named one of the 100 Sexiest Women in the World by FHM magazine, Steenkamp was a contestant in the reality-TV show "Tropika Island of Treasure", which aired in South Africa after her death.

She met Pistorius in 2012 and accompanied him to the South African Sports Awards. She worked as a paralegal and was an advocate against sexual abuse.