The main villain in Hitman: Absolution is Blake Dexter, played by Cowboys & Aliens star Keith Carradine.
Agent 47's handler is Diana Burnwood, played by White Collar's Marsha Thomason. Diana is said to have a "close relationship" with Agent 47, Hollywood Reporter revealed.
"Diana is 47's only true human contact," Thomason said. "They've known each other an extremely long time, and in the Hitman world, she is what Q is to James Bond. So she sets the assignments, tells him where to go and who to kill."
"The character I play in Hitman: Absolution is as multidimensional as any well-imagined character should be," Carradine said.
"The vividness of the world entered by the gamer hinges on detail. To fully engage the attention of the player requires nothing less than the most completely realized universe of geography and personality."
Developer IO is working with a dozen Hollywood actors for the hotly-anticipated game, due out next year.
Actors are required to provide performance capture and voice over work, conducted in Giant Studios, which James Cameron used for blockbuster movie Avatar.
IO has captured "complex scenes" with up to seven actors on set at once. Absolution focuses on the emotional stories that evolve, director Tore Blystad said.
"We had actors like Marsha and Keith come in and do full-body acting with facial and voice being captured simultaneously in scenes.
"Some of these scenes were very complex with all kinds of props and interactions amongst the actors."
PC, PlayStation 3 and Xbox 360 game Absolution was announced two days ago with a brief teaser trailer, below.
Agent 47 takes on "his most dangerous contract to date", publisher Square Enix said. "Betrayed by those he trusted and hunted by the police, he finds himself at the centre of a dark conspiracy and must embark on a personal journey through a corrupt and twisted world, in his search for the truth."
Absolution has been built "from the ground up" by IO using its new proprietary Glacier 2 technology.
Blystad described it as "more stylised, more serious, and darker this time around in both the story line and the visuals".
Agent 47 goes on different missions throughout the US, with part of the game taking place in Chicago.
A new Hitman movie launches next year to coincide with the game. Daniel Casey (Jimmy Six) has written the script. The film is said to have an original story and characters, "but will retain the look and feel of the new game".
"The hope is that the movie will be going in a similar direction, and then when they both come out they will speak the same language. They won't follow the old Hitman games, but rather go with this newer direction."