A tearful Oscar Pistorius on Friday made his first appearance in court since the shooting death of his girlfriend, Reeva Steenkamp.

He was wearing a dark suit, tie and blue shirt when he appeared in the Pretoria Magistrates Court.

The 26-year-old South African sprinter broke down in the dock as magistrate Desmond Nair formally charged him with murder.

Pistorius had spent the night in custody after blood-alcohol and other tests delayed his appearance before a magistrate.

Police played down reports he fired after mistaking the 29-year-old Ms Steenkamp for a burglar.

Pistorius became an international celebrity during last year's London Olympics, as the first double-amputee to line up beside able bodied competitors.

He was publicly adored in his native South Africa, though questions had been raised about his colourful private life replete with glamorous girlfriends, guns and fast cars.

Police were called to his upscale Pretoria home by neighbours who heard gunshots inside the gated community.

Police spokeswoman Denise Beukes said the 9mm pistol used in the shooting was registered to Pistorius.

Authorities said he was the only suspect in the case and prosecutors would oppose any request for bail.

His arrest rocked South Africa, where he had been considered a hero.

''Obviously we are shocked,'' his father Henke Pistorius said. ''He is with the police and the matter is in the hands of the authorities.''

Australian track athlete and fellow Olympian Tamsyn Lewis described Pistorius as ''an affable character'' whose celebrity was comparable with that of Usain Bolt.

''I am completely shocked with what's transpired,'' she said.

''If you were going to pick an athlete for this to happen, you would never put your hand up and say Oscar Pistorius.

''He's just a down to earth, friendly guy. It's just such a shock.''

Authorities have poured cold water on media reports Ms Steenkamp, once an FHM cover girl, had sneaked up on her lover, suggestions fuelled by her tweet the day before.

''What do you have up your sleeve for your love tomorrow??? #getexcited #ValentinesDay'', she wrote.

Police were talking to neighbours who heard disturbances on Wednesday evening and around the time of the shooting. There had been previous allegations of domestic disputes at Pistorius's home.

''There were always rumours attracted to Oscar Pistorius, but most of them I just put down to him being a celebrity,'' said Kyle Wood, a 25-year-old fellow resident of the Silverlakes community.

In 2009 Pistorius spent a night in jail after allegedly assaulting a 19-year-old woman at a party.

He has often spoken publicly about his fondness for guns. Last year he told a newspaper he sleeps with a pistol, machine-gun, cricket bat and baseball bat for fear of burglars.

There are an estimated 1.5 million gun owners in South Africa, where crime remains a major problem.

Many residents keep weapons at home and equip their houses with electric fences and panic buttons that summon heavily armed guards within minutes.

In November, Pistorius tweeted about arriving home and hearing the washing machine on ''and thinking it's an intruder to go into full combat recon mode into the pantry! waa.'' AFP/DPA