He’s not in the Green Lantern cast list, but I’m told that Oscar-nominated The King’s Speech star Geoffrey Rush plays an important role in the Martin Campbell-directed Warner Bros film that stars Ryan Reynolds. Sources said that it’s Rush who provided the voice for Tomar-Re, the scientist who works alongside the title character in the Green Lantern Corps. Tomar-Re, who looks a bit like the Creature From the Black Lagoon, has a long history in the DC Comics version of Green Lantern. Warner Bros will unveil footage at CinemaCon in Las Vegas tomorrow, so perhaps some of the mystery might be cleared up by Thursday.

Less certain is who’ll provide the voice for the character Kilowog. Speculation has centered on Michael Clarke Duncan. I’m told that he’s certainly a contender but a final decision hasn’t yet been made. The film opens June 17, so a decision will be made shortly.