Disgraced Paralympic gold medallist Oscar Pistorius will be sentenced in June for the 2013 murder of his girlfriend Reeva Steenkamp, after his original conviction was upgraded from the lesser charge of manslaughter.

Pistorius, 29, known as "Blade Runner" for the carbon fibre prosthetic blades he used to race, faces a minimum 15-year jail sentence and cannot appeal after the country's top court ruled in March that he had exhausted all his legal options.

Dressed in a black suit, he showed no signs of emotion during the brief court appearance and spoke on his cellphone as he left the court. He denies killing Steenkamp, saying he mistook her for an intruder at his home.

"The matter is postponed to the 13th of June 2016, High Court Judge Aubrey Ledwaba said of the final sentencing "It will be heard until the 17th of June 2016."

Outside the court, a group of people in white t-shirts gathered in support of Pistorius holding placards.

Pistorius initially received a five-year sentence for "culpable homicide", South Africa's equivalent of manslaughter.

He was released from prison last October after almost a year behind bars and allowed to serve out his term under house arrest on his uncle's property in a wealthy suburb of Pretoria.

But in December, the Supreme Court upgraded the conviction on appeal to murder. He was allowed to stay at his uncle's pending the final decisions on appeals and sentencing.

The runner, whose lower legs were amputated when he was a baby and went on to become a global sporting hero, has lost millions of dollars in endorsements and sponsorships.

He reached the pinnacle of his fame in London 2012 when he became the first double amputee to run in the Olympics, reaching the 400-metres semi-finals.

Steenkamp's parents did not attend the hearing.

The case has prompted a fierce debate in a country beset by high levels of violent crime. Some rights groups had said the white track star got preferential treatment