An explosive book - Oscar vs The Truth -- written by two South African brothers says Oscar Pistorius hit his girlfriend Reeva Steenkamp with a cricket bat before shooting her dead. (Oscar Pistorius Sentencing Postponed to June)
Calvin and Thomas Mollett, both forensic experts, conducted a painstaking analysis of evidence and photographs, before laying out a raft of theories about Steenkamp's murder on Valentine's Day in 2013, reports The Sun.
The double-amputee killed Reeva Steenkamp, a model and law graduate, on Valentine's Day three years ago, saying he mistook her for an intruder when he shot four times through the door of his bedroom toilet.
He was released from jail in October to live under house arrest at his uncle's property in Pretoria after serving one year of his five-year prison sentence for culpable homicide -- the equivalent of manslaughter. Pistorius faces a minimum 15-year jail term when he appears for sentencing in June.
The disgraced Paralympic gold medallist also shot Steenkamp in the arm with an air rifle, as she tried to flee, according to a year-long, detailed forensic investigation by the brothers.
Two wounds on Steenkamp's back appear to match up with markings on the toe of a cricket bat that was found on the floor in Pistorius' bedroom, The Sun reported.
Markings and tears on the rubber handle of the bloodied cricket bat appear to be consistent with a violent struggle between an assailant and victim, say the brothers in their book.
During the trial, Pistorius claimed he had only used the bat to try and smash down the door of the bathroom upon realising he had accidentally mistaken Steenkamp for an intruder and killed her with four shots from his revolver.
Photographs in their investigation also revealed a 4.5mm bullet hole in a bedroom door, believed to have been fired from Pistorius' air rifle.
A similar bullet wound was located on Steenkamp's arm, which the Mollett brothers say proves the Blade Runner shot at his girlfriend during a heated argument that raged for an hour on the night she was murdered.
"The argument didn't just take place in the bedroom but elsewhere in the house as well," said the report. "It sounded like the woman was arguing with someone -- although she couldn't hear a second voice.
"The female voice was quiet for periods ranging from five to 20 minutes, and lasted for about an hour.
"Around 3am Reeva started fearing for her personal safety and locked herself in the toilet.
"Oscar went after her with a cricket bat - infuriated that she locked herself away from him - and to scare and frighten her, he hit the door with the cricket bat about 2-3 times and also hit the steel plate against the bathtub wall."
The Mollett brothers also discovered a range of injuries on Steenkamp's body that were never raised, nor explained, at the trial, according to The Sun.