Sydney's Joel Edgerton, a blue-eyed blond from Blacktown, has a shaved head and a deep tan to play the lead Egyptian role of pharaoh Ramses II.

A porcelain-pale Sigourney Weaver plays his mother, Queen Tuya.

US Breaking Bad star Aaron Paul features as Israelite leader Joshua and the English-born Christian Bale takes on the role of Moses.

Tariq Nasheed, a director of the race documentary series Hidden Colors, has campaigned against the film for "redefining history".

"The storyline takes place in ancient Africa, but all the African Kings and Gods are portrayed by white actors and all the slaves, thieves and 'lower class' Egyptians are played by Black actors," he wrote on Facebook.

"When I saw they have Sigourney Weaver playing an African queen, I was done."

A screenshot of the cast list on movie website IMDB, contrasting the roles of the black and white actors, has been retweeted more than 1100 times.

Some on Twitter have also taken aim at the set, particularly the nose on the Great Sphinx of Giza, saying it gives the statue a European profile.

The Exodus casting is the latest in a long Hollywood history of making actors play different ethnicities, no matter how much dark make-up is required.

Another Exodus actor, Englishman Ben Kinglsey, was rebuked for the heavy whole-body make-up he wore to play Gandhi, even though Kingsley has Indian heritage.

Anthony Hopkins went very orange as Shakespeare's Moor Othello in a 1981 BBC production while Charlton Heston stood up for the right of a white actor to play a Eurasian role in Miss Saigon.

The US legend declared the casting block "obscenely racist" and resigned from the Actors Equity labour union in protest. 

I just let out the loudest cackle. Oh. Hollywood pic.twitter.com/otchhdj36e — DarkSkintDostoyevsky (@daniecal) July 27, 2014

#Exodus will have an all-"white" cast. Many "Whites" are still racist, & are "WHITEWASHING" every AFRICAN culture. http://t.co/hJHSha3AGW — Yorel Tifsim (@YorelTifsim) July 2, 2014