Christian Bale has slammed his character Moses as "barbaric" ahead of the upcoming move Exodus: God and Kings.

"I think the man was likely schizophrenic and was one of the most barbaric individuals that I ever read about in my life," Bale told reporters.

"He's a very troubled and tumultuous man who fought greatly against God, against his calling."

Bale has been critical of the Hebrew character before, describing him as a "mercurial", though he has admitted that his own Bible knowledge is lacking.

And as with all biblical epics that make it to the big screen, there has been much discussion over how accurate to the original text the final cut will be.

Director Ridley Scott said Moses' story is "one of the greatest adventures and spiritual experiences that could ever have been," but critics have expressed concern that attempts to adapt the movie to fit Hollywood's standards will mean key details are lost.

Attracting particular interest has been the revelation that in the film, it is not God who parts the Red Sea, but an earthquake.

"You can't just do a giant parting, with walls of water trembling while people ride between them," Scott said in an interview with Entertainment Weekly.

"I didn't believe it...when I was just a kid sitting in the third row. I remember that feeling, and thought that I'd better come up with a more scientific or natural explanation."

Of Bale's latest comments, founder of Faith Driven Consumer, Chris Stone, told the Hollywood Reporter, "There's nothing in the biblical history that supports that. It's an indication that there will be a tremendous disconnect between Bale's interpretation and the expectations of the market."

Christian writer Brian Godawa also told the news site: ""It's accurate to portray Moses as an imperfect hero, so Christians won't take issue with that. But to be so extreme as to call him one of the most barbaric people in history, that sounds like he's [Bale] going out of his way to distance himself from the very people you'd think he wants to appeal to.

"It tells me that he's worried about Hollywood peer approval while looking down on the public, because he certainly doesn't want to be associated with the religious or the far right."