'I Came By': George MacKay and Percelle Ascott on how thriller is uniquely London (exclusive)

Watch: George MacKay and Percelle Ascott on why I Came By needed to be in London

The cast of new Netflix movie I Came By have revealed it was "magical" to make such an ambitious film entirely in London — where they both grew up.

Directed by Under the Shadow filmmaker Babak Anvari, the movie follows a pair of graffiti artists (George MacKay and Percelle Ascott) who enter the orbit of Hugh Bonneville's retired judge — a man hiding a dark secret.

Ascott, whose previous credits include Doctor Who and Tin Star, said filming on familiar streets gave an extra level of excitement and intensity to the project for him.

Read more: Kit Harington on filming Marvel action in London

"For me, it was quite magical, because we're filming on locations that I grew up in," the star told Yahoo Entertainment UK.

He added: "There was one particular location that was a school my grandfather went to, so again it was just nice to have that experience of filming in your London.

"We were talking about where these boys were from and finding that London, and really talking about the kind of graffiti background and all the kinds of choices that that make these characters, basically."

Read more: I Came By cast say movie is "a mirror to society"

Ascott and MacKay play politically motivated graffiti artists, who break into the homes of wealthy Londoners and daub the titular phrase on their walls in protest at inequality.

MacKay said that I Came By's depiction of the UK's capital — illuminating the difference between the wealthy and those lacking the same privilege — "feels like the London that we know" having lived there.

"You kind of get a couple of postcard moments, but it isn't all the London Eye and Big Ben. It feels very grounded in the London that we know," he said.

MacKay added: "That's what the film is looking at. It's so multi-dimensional in terms of all social aspects of it.

Read more: New movies and TV on Netflix in August

"London feels like the perfect setting because we all live on top of each other and intertwined. That melting pot feels particularly true of this city."

The lads' graffiti crusade takes a dark turn when MacKay breaks into the home of Bonneville's character — an esteemed judge with a history of helping refugees — only to be stunned by what he discovers.

This is the first of director Anvari's films to shoot in London, despite the city being home for the filmmaker, and he initially came up with the idea 20 years ago — expecting it to be his first feature.

"It is my first time actually shooting in London, which is home — and it felt great. I want to, if I can, do everything in London," Anvari said.

Read more: Things you might not know about Hitchcock classic Psycho

The director added: "It's a Hitchcockian neo-noir film. Hitchcock is from Britain, but rarely do these type of films get made here.

"Americans do it really well. Even the French do it very well. So why not just take inspiration from the master and do that type of film over here in London?

"London, as a city, is excellent for a neo-noir film. It's pretty much like a character in the story, you know.

"It felt good. I felt good after wrapping, going home and sleeping in my own bed."

Read more: I Came By shows dark side of Hugh Bonneville

The film's cast includes Line of Duty star Kelly Macdonald as the mother of MacKay's character, as well as Yazdan Qafouri, who plays an Iranian refugee working as a masseur.

I Came By is in UK cinemas now ahead of its Netflix debut on 31 August.

Watch: Trailer for I Came By