There has been many a Hollywood actor portraying South African anti-apartheid activists in movies, but none would be as weird as Forest Whitaker playing retired archbishop Desmond Tutu.

Reports in the US suggest that the 50-year-old Whitaker might be preparing to play his most demanding role yet, in a movie to be directed by Roland Joffe.

The Oscar-winner 's deep voice would have to be greatly manipulated to emulate the arch's high pitch , among their many differences. The movie is reportedly based on Michael Ashton's play The Archbishop and the Antichrist , which was read at London' s Soho Theatre in May.

Explaining the play in 2010, Ashton told The Telegraph newspaper: "We're in 1996 at the time of the Truth and Reconciliation Commission hearings, which he [Tutu] was the chairman of. Tutu is finding it difficult to reconcile forgiveness with amnesty and is having a crisis of conscience and faith. "It's a play that I'm proud of."