Pretoria — Paralympian Oscar Pistorius arrived in a police convoy at the Mamelodi Day Hospital on Thursday following the Valentine's Day shooting of model and law graduate Reeva Steenkamp at his home.
It was not immediately clear why he was there. He was taken to the clinic at high speed following a period at the Boschkop police station in the morning.
The management of the publicity agency that Steenkamp retained confirmed she had been shot dead.
Sarit Tomlinson, MD of Capacity Relations, said in a statement: "We can confirm that Reeva Steenkamp has passed away... Our thoughts and prayers go to the Steenkamp family, who have asked to have their privacy respected during this difficult time, everyone is simply devastated.
"She was the kindest, sweetest human being; an angel on earth who will be sorely missed."
Outside Pistorius's home, Steenkamp's model friend Mashadi Motsogi was in tears.
She had seen on Twitter that Steenkamp had been shot, but did not believe it.
"It was only on my way to campus when I saw journalists come in front of the estate, when I realised that it might be true, that she might be dead. I know Oscar stays here. When I called here, he did not reply. He did not answer my call."
She described Steenkamp as a "friendly person, always willing to help other people".
"She never snapped," said Mogotsi, who had looked to Steenkamp, an established model, for advice.
"I have lost a friend," she said, tears streaming down her face.
She said it did not make sense that her friend died in a secure complex.
"Look, security here is safe. We moved to this area for security reasons. It does not make sense to me that my friend was shot, mistaken for an intruder."
Pistorius was expected to appear in the Pretoria Magistrate's Court later on Thursday.