A new and unconfirmed report over at ThinkMcflyThink indicates Warner Bros. Pictures is deliberately throwing its casting net wide with its eventual "Justice League" film. Why? To create a mix of nationalities amongst the cast members.
This "United Nations approach" to casting can already be seen in "Batman vs. Superman" - British-born Henry Cavill as Superman, U.S.-born Ben Affleck as Batman, Israel-born Gal Gadot as Wonder Woman, and New Zealand-born Callan Mulvey who is rumored to be playing the villain Metallo.
But the report's main bit of casting speculation is that actors from all ethnicities are currently being tested to portray Lex Luthor, the big role that they are trying to lock down at the moment. Denzel Washington was reportedly the first choice, while Idris Elba also made the list.