Former friend Mike Gilbert claims the actor and former American football star stabbed Nicole Brown Simpson outside her apartment on 12 June 1994.
OJ confessed to me. Theres no doubt in my mind, Mike writes in his new book How I Helped OJ Get Away With Murder: The Shocking Inside Story Of Violence, Loyalty, Regret And Remorse.
'[He said to me] "If Nicole hadn't opened the door with a knife in her hand she'd still be alive,"' Mike claims.
He also says he helped OJ get off the charges by suggesting he bloat his hands so they wouldn't fit the gloves produced during the court case.
OJ, now 60, was acquitted of murdering Nicole and her friend Ronald Goldman after the lengthy and high-profile trial.
His rep Yale Galanter denies Mikes claims, calling him a delusional drug addict'.