'Pistorius steroids can heighten aggression'
South African Olympian 'to be tested for substance'18 February, 15:26
The South African Olympic and Paralympic athlete claims he shot Steenkamp after mistaking her for a burglar.
However local media report that neighbours called the police two hours prior to the shooting due to a heated argument between the two.
Police also reportedly recovered a bloody cricket bat from the bedroom and said that Steenkamp's head had been battered. Media have reported that there was evidence of heavy drinking before the shooting took place. A bail application has been set for Tuesday while Pistorius remains in police custody.
The case has attracted strong media attention due to the high profile of the suspect, who is is known as the "blade runner" because of the blade-like carbon-fibre prosthetics he runs with.
South African media have already re-named him the "blade gunner".
Pistorius made sporting history at last summer's London Games when he became the first amputee sprinter to compete in the Olympics proper.
The athlete reached the 400m semi-finals in the London 2012 Olympics and is a multiple Paralympic gold medallist.