In a statement, the Pistorius family said no new evidence existed to back up the allegations and called the book's authors "amateur forensic hobbyists" who were only seeking fame and money. It also condemned what it called the media's "often-vicious" parallel trial against him.
In their book "Oscar vs The Truth," brothers Calvin and Thomas Mollett wrote they had seen new evidence, including marks on the back of Reeva Steenkamp's body that indicated Pistorius had hit her with the bat before he killed her. "This is yet another attention-seeking, money-making exercise, this time by two citizens with detective fantasies who have a history of latching onto high-profile cases after the fact," the Pistorius family said.
The family statement comes the same week Pistorius appeared in court for the first time since his conviction for shooting Steenkamp was upgraded from manslaughter to murder following an appeal by prosecutors. He now faces a possible 15 years in prison and will be sentenced in June.
Pistorius' cricket bat was a key part of the evidence at his murder trial. His defense claimed it was bloodied and damaged after he broke down a toilet cubicle door with it to get to Steenkamp after shooting her accidentally thinking she was an intruder. He then left it on the bathroom floor while he tried to help his girlfriend, the defense argued.
In finding Pistorius guilty of murder on appeal, South Africa's Supreme Court didn't rule he intentionally killed Steenkamp. It ruled he was guilty of murder according to a section of South African law because he realized that someone might die as a result of his actions, and went ahead anyway when his own life was not in danger.
Pistorius' sentencing hearing will run June 13-17, when the same judge that initially acquitted him of murder will decide his new sentence. South Africa has a minimum sentence of 15 years in prison for murder unless an offender can show exceptional circumstances.