The crime drama stars Costner as a violent Death Row inmate who is selected as a guinea pig for a new medical experiment involving the transfer of memories from one brain to another to help CIA officials track down a dangerous hacker.

Eve portrays a CIA agent, with Oldman as her boss, and she reveals heading to set each day, alongside fellow co-star Tommy Lee Jones, was like going to acting school as she was constantly learning from the Hollywood veterans.

"He's such a lovely man, Gary Oldman," she smiled on U.S. breakfast show Today. "I loved the film... Kevin Costner is just the last cowboy in America, he even wears cowboy boots and you just melt when you watch someone who is as good as him, so I really enjoyed it.

"Watching them all do their thing throughout the experience was... incredible actually, and I learned a lot from Gary, who takes it all in his stride."

Eve also enjoyed researching her role as a CIA operative: "Just looking, investigating the idea of being CIA agent was fascinating because the level of secrecy they have to maintain in their lives," she said. "They can't go home and... share their life, and that must be very alienating, so it's quite interesting to investigate the psychology of a CIA agent."

As for the film's fictional concept of memory transfer, Eve believes it's only a matter of time before top neurosurgeons and medical experts figure out a way to save vital memories.

"If we could do it, we would," she explained. "My grandmother had Alzheimer's and the loss of memory is a serious thing, but interestingly, you hold on to the love you had, you remember love, you remember the romantic moments or the family moments. But I guess this is almost like a high concept superhero movie idea, that there's a frontal lobe you can kind of transfer into someone else's head, and science is moving at a fast pace, so it's probably not a pipe dream..."

Criminal opens in the U.S. on Friday (15Apr16).