South African Paralympic athlete Oscar Pistorius has been arrested over the fatal shooting of his girlfriend at his home in Pretoria, local media say.
Police confirmed to local media that a woman - who died at the scene - was shot in the head and arm.
The precise circumstances surrounding the incident are unclear. Reports say he may have mistaken her for a burglar.
The 26-year-old - known as the "blade runner" - was the first double amputee to run in the Olympics.
"We found a 9mm pistol at the scene. A 26-year-old man was taken into custody," police spokeswoman Katlego Mogale told Reuters news agency.
Local media say the body was removed from the scene.
South Africa has among the highest rates of crime in the world and many residents keep weapons to protect themselves against intruders.
But South Africa does have a careful vetting process before awarding gun licenses, Erika Gibson of Beelt newspaper told the BBC.
Pistorius races wearing carbon fibre prosthetic blades after he was born without a fibula in both legs.
He reached the 400m semi-finals in the London 2012 Olympics.
For years he dominated in his category at successive Paralympic Games after winning medals at the 2004 Athens Games.
