Johannesburg, Jan. 5 (AFP) - At the 2012 London Olympics, before 80,000 roaring fans and a constellation of camera flashes, it took Oscar Pistorius 45.44 seconds to become a global icon. A year later, he shot his girlfriend Reeva Steenkamp dead with four bullets.

The 37-year-old former athlete convicted of murder was released from prison on parole Friday having served more than half his sentence, nearly 11 years after the crime that shocked the world.

In the early hours of Valentine's Day 2013 at his upmarket Pretoria home, he shot through the closed door of his bedroom toilet, killing the 29-year-old model Steenkamp.

He later said he had mistaken her for an intruder.

During his 2014 trial in a windowless courtroom, sponsors dumped him and he was forced to sell his homes to cover mounting legal bills.

A five-year conviction for manslaughter was upgraded to murder on appeal and in July 2016 he was sentenced to six years, less than half the minimum term for the charge.

In 2017, the Supreme Court of Appeal more than doubled that jail term to 13 years and five months after the state appealed that the sentence had been unduly lenient.

Prosecutors had argued that Pistorius failed to show genuine remorse.

The department of correctional services confirmed his release early Friday after he had been quietly whisked away from the Pretoria prison out of sight from the hordes of press camped outside the gates of the facility.

His parole conditions include undergoing therapy for anger and gender-based violence issues, abstaining from drinking alcohol or consuming other substances, and completing community service.

- Darker side -
The high-profile murder trial that gripped the world exposed the now 37-year-old's darker side, offering glimpses of a dangerously volatile man with a penchant for guns, beautiful women and fast cars.

In 2009, he had spent a night in jail after allegedly assaulting a 19-year-old woman at a party in a case that was settled out of court.

He was accused of firing a gun through the sunroof of an ex-girlfriend's moving car.

Weeks before he shot Steenkamp, he discharged a gun by accident at a Johannesburg restaurant.

The sprinter slept with a pistol under his bed at his home in a high-security estate for fear of burglars.

Steenkamp's mother June, said in March she does not believe Pistorius has told the truth about what happened.

Pistorius was born in 1986 in Johannesburg without fibulas (calf bones).

His parents decided when he was 11 months old to have his legs amputated below the knee so he could be fitted with prosthetic legs.

This allowed him to play sports and he excelled, concentrating on running only after fracturing a knee playing rugby.

"It was never made an issue. My mother would say to my brother, 'You put on your shoes and Oscar, you put on your legs. Then meet me at the car,'" Pistorius said in a 2011 interview.

- 'Man, Superman, Gunman' -
A middle child whose parents divorced when he was six, he has had a problematic relationship with his father Henke. His mother died when he was 15.

In 2004, just eight months after taking to the track, he smashed the 200-metre world record at the Athens Paralympics.

At the 2008 Beijing Paralympic Games he took the 100m, 200m and 400m sprint titles and launched a battle to take part in able-bodied athletics, overcoming arguments that his custom-built carbon-fibre running blades gave him an unfair advantage.

In 2012, he made history by becoming the first double-amputee to compete at both the Olympics and Paralympics.

"He is the definition of global inspiration," TIME magazine proclaimed in its 2012 list of the world's most influential people.

Less than a year later, Pistorius featured on the cover with the words "Man, Superman, Gunman".