Last month, Michael Fassbender (X-Men: First Class) joined the cast of director Ridley Scott‘s forthcoming film called Prometheus, which is set to star Noomi Rapace (Sherlock Holmes: A Game of Shadows). Earlier this month, we reported that Charlize Theron (Snow White and the Huntsman) was in final talks to join the cast as well.

Now, The Daily Mail reports that Idris Elba (Thor), Sean Harris (A Lonely Place to Die), and Kate Dickie (The Pillars of the Earth) have joined the cast of Scott’s sci-fi thriller. No information has been released about the roles the three have signed on to play.

Speaking about keeping the Prometheus script from leaking, Scott told them that cast-members had to sign secrecy clauses, and aside from one exception where a security courier flew to an actor’s foreign location and stood guard for two hours while the screenplay was perused, they were only allowed to read the story if they visited Scott’s production office.

Scott said,

“I was insistent that the script not leak onto the internet, where it gets dissected out of context, which spoils it for everyone.”

Despite persistent rumors that Prometheus is still technically a prequel to Alien, Scott insists that it’s not:

“It’s the story of creation, the gods and the man who stood against them. It’s not a small film. I’m using the giant James Bond 007 stage at Pinewood and six other sound stages to film it”.

Prometheus is slated to hit theaters on June 8, 2012.