A prosecution witness at O.J. Simpson's Los Angeles trial for the murder of his ex-wife is the leading suspect as ghostwriter of Simpson's book "If I Did It."

Pablo Fenjves, a screenwriter and producer, lived near Nicole Brown Simpson in Brentwood in 1994. He testified in the trial about hearing the cry of a dog.

Fenjves, whose screenwriting career was on a downward slope, made a new career as a ghostwriter, the Los Angeles Times reported. While he has not admitted doing the Simpson book, he is the writer behind books bearing the name of Bernie Mac and Richard Pryor's daughter, Rain, among other people, the newspaper said. He is one of the writers employed by Judith Regan, the editor who packaged the Simpson book.

Plans for publication of the book by Regan's imprint at Harper Collins and a tie-in interview on corporate cousin Fox Broadcasting were scuttled after a public outcry.

Fenjves has not acknowledged any involvement with the book. Simpson, on the other hand, in an interview on WTPS-AM in Miami not only named Fenjves as the ghostwriter but suggested that he knew things only the killer could have known.