Oscar Pistorius removed his prosthetic legs in a South African courtroom as part of his defence team's argument that the double-amputee athlete, convicted of murdering girlfriend Reeva Steenkamp, deserves leniency when he is sentenced.

"Pity will play no role in the sentence," chief prosecutor Gerrie Nel countered, asking Judge Thokozile Masipa to send the former track star to prison for 15 years, the minimum sentence for murder in South Africa.

Judge Masipa will announce Pistorius's sentence on July 6, she said at the end of three days of evidence and arguments in Pistorius's sentencing hearing.

Pistorius is currently under house arrest after an appeals court overturned an initial manslaughter conviction against him and changed that to murder. He served one year in prison for manslaughter.

Judge Masipa, who initially acquitted Pistorius of murder at his trial in 2014, must now re-sentence him.

Judge Masipa on Wednesday lifted a ban on the publication of graphic photographs of the gunshot wounds Pistorius inflicted on Ms Steenkamp - which included a severe head injury -when he shot her multiple times through a toilet cubicle door in his home. Judge Masipa lifted the restrictions after a request from Ms Steenkamp's father that people be allowed to see them.

The most dramatic image of the sentencing hearing was Pistorius walking unsteadily without his prosthetic legs in the courtroom Wednesday.

Defence lawyer Barry Roux asked Pistorius to remove his prostheses and the Olympian, who had taken off his suit and put on a T-shirt and running shorts during a recess, then hobbled across the courtroom.

Pistorius was unsteady at times, holding on to wooden desks and helped by a woman at one point. He then returned to a bench where he sat alone, head bowed, and wiped away tears.

The demonstration drew gasps from some onlookers in the courtroom.

"I don't want to overplay disability," Mr Roux said ahead of the demonstration, "but the time has come that we must just look (at Pistorius) with different eyes".

Pistorius was not wearing his prosthetic legs when he fired the fatal shots on Valentine's Day 2013; he testified at his murder trial that he felt vulnerable and thought an intruder was in the house.

Mr Roux said: "It was not the man winning gold medals that must be judged" but rather "a man standing on his stumps at 3 o'clock in the morning in the dark that must be judged".

Prosecutors charged that Pistorius intentionally killed Ms Steenkamp after a fight.

Chief prosecutor Mr Nel said Pistorius should get the minimum sentence of 15 years, arguing that he had not shown genuine remorse a well as noting the seriousness of the crime and the devastating impact on Ms Steenkamp's family. Mr Nel asked Judge Masipa not to forget that Pistorius shot four times into a toilet cubicle from close range when he killed Ms Steenkamp.

"He intended to shoot someone in the bathroom. He did," Mr Nel said.

A judge can reduce the minimum sentence of 15 years for murder in some circumstances. While prosecutors are seeking at least 15 years in jail, Pistorius's defence argued that he should be spared any more prison time and be allowed to do community work with children.

Mr Nel also addressed the defence argument that Pistorius is a "broken man" because of the grief from killing Ms Steenkamp and the trauma that followed as the world focused on his case. Mr Nel referred to the emotional testimony a day earlier of Barry Steenkamp, father of the victim.

"If you ever want to talk about a broken man, we saw a broken man there," Mr Nel said of Barry Steenkamp.

Mr Roux had begun his arguments by saying there were misconceptions over Pistorius's murder conviction, and "substantial and compelling circumstances" existed that would allow the judge to deviate from the 15 years.

Mr Roux was trying to show Pistorius was guilty of a "less serious murder," prosecutor Mr Nel said. "That can never be the case... We feel a long-term imprisonment and the minimum sentence should be imposed."