South African Paralympic star Oscar Pistorius has been arrested after his model girlfriend was shot dead at his home.
According to local media reports, Reeva Steenkamp, 29, may have been mistaken for an intruder at the property in the Silver Lakes Golf Estate in Boschkop in Pretoria.
There was speculation the shooting may have been a Valentine’s Day surprise gone wrong.
Pistorius is known as the Blade Runner because of the ground-breaking prosthetics he uses for racing.
He had been expected to race in Australia in March.
Steenkamp, described in her Twitter biography as a model, cover girl and law graduate, had tweeted about Valentine’s Day on Wednesday, writing: “What do you have up your sleeve for your love tomorrow??? getexcited ValentinesDay”.
Police spokeswoman Katlego Mogale told the South African Press Association police were called to Pistorius’ home early on Thursday following the shooting.
She said: “Paramedics declared the woman dead on the scene and police proceeded with their investigation. The woman sustained wounds to her head and the upper body.”
A 9mm pistol was recovered. According to unconfirmed reports four shots were fired.
Pistorius, 26, was expected to appear in court on Thursday. Police said a case of murder was being investigated.
The athlete, who lives on a guarded estate, appeared to have serious concerns about his safety.
He was said to keep weapons at his home and sleep with a revolver by his side.
A journalist from the UK’s Daily Mail who interviewed Pistorius noted: “This being South Africa, one baseball bat and one cricket bat lie behind Pistorius’ bedroom door.
“A revolver is at his bedside. A machine gun by his window.”
During the interview, published in August, he described himself as “really blessed”.
He told the paper: “All I want is not to spend my career discussing my legs.”
He made history at the London 2012 Olympics when he became the first amputee sprinter to compete in the able-bodied Games, running in the 400m and 4x400m relay.
The Johannesburg-born athlete, who was born without fibulas in his legs and had the limbs amputated below the knee when he was 11 months old, had to win a legal battle over his blades with the International Association of Athletics Federations (IAAF) in 2008 for the right to compete in able-bodied competition.
Tropika Island of Treasure - an entertainment show starring Steenkamp due to be broadcast this weekend - posted a tribute to Steenkamp on its website.
It says: “We are deeply saddened and extend our condolences to Reeva’s family and friends.”
Athletes joined fans in paying tribute to Steenkamp.
On Wednesday Pistorius was active on his Twitter account, retweeting South African movie channel MNet.
The tweet was about a film the channel is showing as part of its Oscars film awards celebrations - a campaign Pistorius is a brand ambassador for, according to his website.
Just three days ago, Pistorius tweeted about his excitement regarding his first race of 2013, accompanied by a photograph of him in action.
he Tropika Island of Treasure website also features a profile of Steenkamp in which she is described as a top model and reality television star who “prefers to read a book on her off days and spend quality time with friends and family”.
The profile says: “Reeva was born in Cape Town and moved to Port Elizabeth as a child where she continued her studies after matriculating, eventually graduating with a degree in law.
“She moved to JHB (Johannesburg) six years ago after being scouted and named the first face of cosmetics giant Avon South Africa.
“Since then, Reeva has travelled between JHB and Cape Town to film and shoot some of SA’s leading campaigns and commercials.
“Toyota, FHM, Clover and Italian brand Zui are some of the more prestigious clients she has worked for.
“With a background in TV presenting, once the live roaming presenter for FashionTV in South Africa, Reeva is currently working on some major projects that include smaller TV roles as well as a lead in a new reality TV show.
“Reeva has a passion for cars and cooking.”
The International Paralympic Committee (IPC) said: “At this time the IPC would like to offer its deepest sympathy and condolences to all families involved in this case.”