Keira Knightley has relished playing a "complicated creature" in Black Doves.

The 41-year-old actress stars alongside Ben Whishaw and Sarah Lancashire in Black Doves, the spy action thriller series, and Keira has revealed that she relishes playing the role of Helen Webb.

She told People: "I think they're very morally ambiguous, incredibly complicated creatures in incredibly strange situations. So it's sort of like, yeah, just watching them and see what will happen is an interesting project."

Ben, 46 - who plays Sam Young in the spy thriller series - also loved playing a complex character.

The actor explained: "They're quite bad -- really bad -- and I think that somehow I find that strangely sympathetic."

Keira has enjoyed a hugely successful career in the entertainment industry, having starred in Bend It Like Beckham back in 2002 - but Keira acknowledges that her life and her career could've easily gone in another direction.

Speaking to The Independent, Keira previously explained: "The adult me is very aware that people can go through very difficult periods in their life, and they do not come out of it with a very successful career and a very healthy bank balance. I feel incredibly fortunate."

Keira acknowledged that she's now achieved a level of respect from the public that didn't exist during her teenage years.

The brunette beauty said: "I think being a 40-year-old woman, people have a different response to you than when you're 18. That's just the way the world is.

"When you're 18, you haven't got much work, you're all image. When you have a career that's 25 years long, and you've got enough stuff to be like, 'Well, that's a body of work; some worked, some didn't' - people can look, and go, 'That's a career.'"

Prior to that, Keira observed that some actors and actresses, including herself, often lean into their anger in order to inspire their on-screen performances.

Keira told the Guardian newspaper: "I think there's an inherent rage to actors. I see that quite a lot. Masked brilliantly but easy to access.

"Not that people behave badly, because generally they don't. But there's a well of anger that opens very quickly.

"It comes from this being such a subjective industry where it is very public when things go wrong. And it's an industry of people searching for a truth that by its very nature they can't find because it's fiction. Maybe that creates the coiled spring, which is where some performances come from."