Oscar Pistorius, the Paralympic star and inspiration to millions around the world, was contemplating his future from a police cell on Thursday night after being charged with murdering his girlfriend (video).

In a drama that stunned South Africa and admirers abroad, Pistorius allegedly fired four bullets into Reeva Steenkamp's head, chest and arm at his home in the capital, Pretoria, in the early hours of Thursday morning.

The life of the glamorous athlete, known as the Blade Runner for his hi-tech artificial legs, has been one of world sport's defining narratives of triumph over adversity, culminating in his appearance at the both the Olympics and Paralympics in London last year.

Yet as the 26-year-old prepared to answer a murder charge and apply for bail at Pretoria magistrates court on Friday morning, a picture emerged of a man with a playboy lifestyle, an intense interest in guns and a taste for living dangerously, suggesting that the world did not know Pistorius as well as it thought.

Steenkamp, 29, a model whose face graced the covers of glossy magazines, had only been dating him for a few months. On Twitter she had written of her excitement about Valentine's Day. "What do you have up your sleeve for your love tomorrow???" she tweeted. "… It should be a day of love for everyone :) may it be blessed!"

Last week she told South Africa's Sunday Times her boyfriend was "an impeccable man who always has her best interests at heart".

Pistorius pictured with Steenkamp in Johannesburg in January. Photograph: Waldo Swiegers/AFP/Getty Images

She had been due to give a motivational talk to school pupils on Thursday, while this weekend she will be seen in a reality TV series, Tropika Island Of Treasure, in which celebrities and ordinary people compete in remote, exotic locations in a variety of daily challenges. News broadcasts showed footage of her being interviewed in Jamaica to promote the series, which producers said would be broadcast as planned.

The model's uncle, Mike Steenkamp, told eNews Channel Africa: "I must just say that her future has been cut short. The family are devastated.

"How it pans out, at the end of the day we will all know the true story. We must never forget what Reeva stood for. She loved people, she loved everybody, her heart went out. At least we know exactly what she accomplished in the past."

He added: "It's a devastating shock. Her whole life, what she could achieve, never came to fulfilment. I hope she's with the angels."

Steenkamp was shot at around 3am in Pistorius's house in an exclusive gated community. Police said paramedics were already at the scene by the time they arrived and Steenkamp was pronounced dead. A 9mm pistol was recovered and there was soon yellow police tape around the grey modern two-storey house, along with crosses marking each door.

Officers said the couple were the only people in the house at the time and there were no signs of forced entry. They added that neighbours heard "screaming and shouting" around the time of the shooting, and that police had been called to investigate incidents of a "domestic nature" at the house in the past.

In 2009 Pistorius was arrested and spent the night at a police station after a 19-year-old woman accused him of assault. No charges were brought due to lack of evidence.

Shashi Naidoo, the owner of Alushi Model Management in Johannesburg, said she knew both Pistorius and Steenkamp and had seen them together a few times. "They were extremely happy," she recalled. "There didn't seem to be any drama but you don't know what goes on behind closed doors.

"Oscar makes a great first impression. He comes over as friendly and engaging. He's a national hero and Reeva is known in her own right. It's a huge shock as they seemed the perfect couple."

Naidoo admitted that her faith in Pistorius had been shaken. "Oscar has had previous charges against him but we always thought he was a good guy. We thought it was people making something out of nothing, as happens to famous people. We didn't believe it."

The news service eNews Channel Africa said it understood Pistorius had told police it was a "horrible accident" and would plead in court that he mistook Steenkamp for a burglar. Such incidents are not unknown in a country where crime is high and fear of crime even higher.

In 2004, for example, the rugby player Rudi Visagie shot dead his 19-year-old daughter after he mistakenly thought she was a robber trying to steal his car in the middle of the night. But police have played down the theory in this case.

After questioning on Thursday, Pistorius left a police station accompanied by officers. He looked down as photographers took pictures, the hood on his grey sweatshirt pulled up, concealing most of his face. Sources said Pistorius had requested the court hearing to take place as soon as possible. But it was postponed until Friday to give forensic investigators time to carry out their work, said Medupe Simasiku, a spokesman for the prosecution.

Pistorius's father said his son was sad following the shooting. "I don't know nothing," Henke Pistorius told SABC radio news. "It will be extremely obnoxious and rude to speculate. I don't know the facts. If anyone makes a statement, it will have to be Oscar. He's sad at the moment."

Oscar Pistorius competing for South Africa. Photograph: David Davies/PA

Pistorius's former coach Andrea Gianni said he hoped it was "just a tragic accident". He told the Associated Press in Italy: "No matter how bad the situation was, Oscar always stayed calm and positive. Whenever he was tired or nervous he was still extremely nice to people. I never saw him violent."

Six months ago Pistorius – who had both his legs amputated below the knee before his first birthday because of a congenital condition – made history when he became the first double-amputee track athlete to compete in the Olympics. He was named by Time magazine last year as one of the world's 100 most influential people. Yet his compelling story has been undercut by a personal life of tabloid fodder.

In February 2009 he crashed a speed boat on South Africa's Vaal river, breaking his nose, jaw and several ribs.

Witnesses said he had been drinking before the crash and officers found alcohol in the wreckage, though they acknowledged they had not conducted a blood test on Pistorius.

In November last year a newspaper claimed Pistorius "threatened to break the legs" of the friend of a man whom he believed had slept with his then girlfriend. The police became involved before the dispute was eventually resolved.

His colourful love life is never far from the gossip columns. Recent media interviews with Pistorius revealed that he kept an assortment of weapons in his home. "Cricket and baseball bats lay behind the door, a pistol by his bed and a machine gun by a window," Britain's Daily Mail noted in a profile.

Pistorius posted a photograph of himself at a shooting range in November 2011 on Twitter, boasting about his score: "Had a 96% headshot over 300m from 50shots! Bam!"

Pistorius enjoyed target shooting with his pistol and an online Nike advertisement featuring the sprinter read: "I am a bullet in the chamber." The advert was removed from his website on Thursday.

An article in January last year in the New York Times magazine described him talking about how he drew a pistol to search his home when his alarm went off the night before an interview.

At Pistorius's suggestion, he and the journalist went to a nearby target range where they fired at targets with a 9mm pistol. At one point Pistorius told the writer: "If you practised, I think you could be pretty deadly."

Asked how often he went target shooting, Pistorius replied: "Just sometimes when I can't sleep."

In a message posted on Twitter on 27 November last year, Pistorius wrote: "Nothing like getting home to hear the washing machine on and thinking its an intruder to go into full combat recon mode into the pantry!"

The incident reignited South Africa's own debate about gun control. Pistorius is far from alone in owning a firearm in what is one of the world's most violent societies, where on average 43 people are murdered a day. Some commentators argue that gated communities, such as Silver Woods where Pistorius lives, are bastions of privilege that actively feed an "us and them" mentality of fear and paranoia.

In 2009 Silver Woods, built around a golf course, was voted "the most secure estate in South Africa", according to its website. It has a three-metre-high wall, electrified fences, armed 24-hour security guards and manned, controlled access.