Morgan Freeman insists playing former South African leader Nelson Mandela in upcoming film The Human Factor will be the most challenging role of his career.

Freeman is currently trying to master Mandela's voice and heavy accent for the movie, which is based on John Carlin's book Playing the Enemy: Nelson Mandela & The Game That Made a Nation.

And Freeman admits he is terrified he won't be able to do the role justice.

He says, "I've met Mandela several times and it's the one role which does intimidate me. How do you play a man like that? You have to get it right - otherwise there's no point." (PAW/WNTRE/LJ)

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