Riz Ahmed wasn't director Michael Pearce's first choice for 'Encounter'.

The 39-year-old actor stars as Malik Khan, a Marine Corps veteran who embarks on a mission to rescue his young sons from a mysterious threat of alien parasites, in the new Amazon movie but Pearce admitted he initially pictured someone else in the role.

Speaking to The Hollywood Reporter, he said: "He wasn’t our initial first choice. It was only when I spoke to Riz about the project that I just looked at the script again and I thought, why can’t we diversify the choices of the people that we’re looking for for this part?

"I’ve been a fan of [Riz’s] for such a long time, it just became so exciting the idea of him in this role. He’s got that steel, laser focus and fortitude and grit and determination that I could really imagine him incredibly playing a Marine. And I hadn’t seen him play that before. He’s also got this warmth and humanity in all of his characters, so I thought that father-son dynamic would be very deeply felt on-screen."

Janina Gavankar plays Malik’s wife Piya Khan in the movie and since the pair are old friends, they decided to work together to name their on-screen kids.

Janina explained: "Riz is an old friend, mostly because the Indian-Pakistani-South Asian diaspora, we’re a very tight-knit community and we’re very supportive of each other. Riz and I have been looking for something to do together for a while. So when I signed on to this, I called him and I was like, ‘do you want to name our kids together?’”