A sobbing Oscar Pistorius was formally charged by a South African magistrate today with murdering his model girlfriend on Valentine's Day.

The 26-year-old superstar sprinter broke down in the dock as magistrate Desmond Nair announced a single charge of killing his lover, blonde covergirl Reeva Steenkamp.

The double amputee, an inspirational hero of last year's London Olympics, sat hunched, audibly crying as Nair considered whether to allow the proceedings at the Pretoria court to be broadcast.

Relatives in the public gallery tried in vain to console the gold medallist.

The 26-year-old South African Paralympian gold medallist sobbed as Pretoria magistrate Desmond Nair announced a single charge of killing his lover, blonde covergirl Reeva Steenkamp.

The double amputee was an inspirational hero of last year's London Olympics, but on Friday he sat hunched and sobbing as the court heard that prosecutors will argue the murder was premeditated, meaning he could face a life sentence.

He was to remain in custody after a bail hearing was delayed until Tuesday to allow the defence more time to prepare.

In a statement issued by Pistorius's family and management company after the court appearance, the fallen star said "the alleged murder is disputed in the strongest terms."

He also offered his condolences to those close to his former lover.

"Our thoughts and prayers today should be for Reeva and her family -- regardless of the circumstances of this terrible, terrible tragedy."

Known worldwide as "Blade Runner" because of his carbon fibre prostheses -- Pistorius is accused of shooting his glamorous lover four times at his upmarket Pretoria home in the early hours yesterday.

She was shot with his 9mm pistol, suffering wounds to the head and hand and died on the scene.

The sprinter had spent the night behind bars and was subject to blood-alcohol, DNA and other tests, as forensics experts continued to work at the crime scene at his home.

Police have poured cold water on initial reports that Pistorius had shot his 29-year-old girlfriend after mistaking her for a burglar.

Police were called to Pistorius's home at around 4:00 am by neighbours who heard gunshots.

The Beeld newspaper, which first broke the dramatic news of his arrest on yesterday, said the shots that killed Steenkamp were fired through a bathroom door.

Pistorius became an international celebrity during last year's London Olympics, inspiring millions as the first double-amputee to compete alongside able-bodied athletes.

Now his apparent fall from grace has equally captured the attention of millions around the world.

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

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

Steenkamp, once an FHM cover girl, was described as "the kindest, sweetest human being; an angel on earth," by Sarit Tomlins of her management agency.

Born in Cape Town, she grew up in Port Elizabeth where she graduated with a degree in law from Nelson Mandela Metropolitan University.

Police have revealed 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 gated 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.