Lily James has joined the cast of Subversion.

The 36-year-old actress will star alongside Chris Hemsworth in the thriller that has been described as "Die Hard on a submarine".

The story centres on a once-promising naval commander (Hemsworth) who is blackmailed by a cartel-like organisation into piloting a dangerous submarine carrying illegal goods across international waters.

He is thrust into a high-stakes game of cat and mouse with a Coast Guard officer (James) in pursuit and must get past blockades and survive perilous threats from both inside and outside the submarine.

The film is being directed by Patrick Vollrath for Amazon MGM and is being produced by Lorenzo di Bonaventura for di Bonaventura Pictures alongside Stephen Shafer and Greg Cohen.

Production gets underway in September in Australia.

Lily recently revealed that she wants to take on "unlikely roles".

She features in the new movie Relay with Riz Ahmed and Sam Worthington and took the part because she is eager to challenge herself professionally.

Lily told The Hollywood Reporter: "Honestly, I was so excited to work with [director] David Mackenzie and Riz that I almost would've done any old thing that they put in front of me.

"That being said, you love to find work that's surprising and characters that take you in a direction you didn't anticipate. And particularly at this point in my career, I want to keep pushing myself to play unlikely roles, roles that surprise me, and have something to get my teeth into. So that [unconventionality] was definitely what was very appealing about this role and story."

The Downton Abbey star recalled how she was impressed by the script for Relay and hopes that audiences are similarly surprised by the thriller's plot.

Lily said: "Relay felt like this really gripping, dark thriller that exposes the world of whistleblowers and the idea of this greater control and always being watched. It felt really surprising, and I was thrilled to get to work with such a unique filmmaker in David Mackenzie. His movies feel so cinematic and grounded and bold and original."

The actress explained how she managed to develop strong chemistry with Riz, despite the fact that the pair barely filmed together.

She said: "Riz is also one of the most exciting actors out there, especially when you see what he's able to convey with no dialogue in the first 20 minutes of the movie.

"The connection we were able to build despite our characters very rarely being in the same room together was a real challenge. And when I watched the movie for the first time at TIFF on the big screen, I was like, 'Wow, it's incredible that there's this great electricity between these two characters when they barely meet.' So it was quite a sleight of hand that David pulled that off in terms of filmmaking."