Oscar Pistorius
Oscar Pistorius faces a minimum of 15 years in prison as South Africa's highest court dismisses his appealGetty Images

Oscar Pistorius apparently beat up his girlfriend Reevan Steenkamp before killing her, a new book has claimed. "[He] battered Reeva with a cricket bat and shot her with a second gun before murdering her in his bathroom," the book titled Oscar vs The Truth, released by South African forensic expert brothers Calvin and Thomas Mollett states. It also contains hitherto unseen pictures from the crime scene.

The six-time Paralympic gold medallist has maintained that he accidentally shot his girlfriend, after mistaking her for an intruder in February 2013. But the forensic expert brothers, who conducted an investigation of their own into the murder, have revealed images of Steenkamp's wounds to her back, arms and shins, which they say were apparently not examined by the police and pathologist. The Sun reported that one picture showed a rifle propped up near where the model died from her injuries.

The Mollett brothers also claimed that the two were involved in a heated argument that turned violent and continued for an hour, before Pistorius murdered his girlfriend.

Thomas told The Sun: "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 two to three times and also hit the steel plate against the bathtub wall."

The book further states that the wound on Steenkamp's left arm is of a similar size to that of a bullet hole in the bedroom door, but post mortem reports have suggested it was "a small irregular bruise".

Pistorius now faces a minimum of 15 years in jail as South Africa's Constitutional Court dismissed his bid to appeal against his murder conviction.