Rafe Spall revealed that Ridley Scott had security guards on the set of Prometheus in a bid to keep the project as secret as possible.
The Brit actor is set to stat in the Alien prequel - which sees Scott return to the sci-fi franchise.
But there has been plenty of hush surrounding the movie.
Speaking to Digital Spy the actor said: "It was so top secret. There were security guards on set, Ridley doesn't want people to find out about it.
"One thing you learn in life is you don't mess with Ridley! He's amazing, an incredible director and perhaps one of the great, living genuine film auteurs."
"Fans of the genre won't be disappointed, and people who have never seen the Alien film won't be disappointed. I think it's going to be brilliant.
"It felt like being part of movie history, dare I say!"
And the movie, as you may expect, has an all star cast that includes Michael Fassbender, Charlize Theron, Noomi Rapace and Idris Elba.
Prometheus is released 1st June 2012.
Tagged in Prometheus Rafe Spall