For all Ben Wheatley’s successes, the director behind cult hits Kill List, Sightseers and last year’s JG Ballard adaptation High-Rise can pinpoint one moment above all others. Spending an afternoon with legendary filmmaker Martin Scorsese. “As far as a career goes, winning awards or going to film festivals and all that stuff is fine,” he says, “but meeting him was the high point of everything I’ve done.”

They spent a few hours together at his office in New York after Wheatley discovered that Scorsese was a fan of Kill List, his breakout 2011 movie about two hitmen caught up in a dangerous occult world. “It was as close as you can get meeting your film god,” he says, citing Scorsese’s Taxi Driver as the film that first made him realise what a director actually does for a living.

Now Scorsese is executive producing Wheatley’s latest, Free Fire – ostensibly his first ‘American’ film, in that this 1970s tale of two gangs squaring up in a warehouse is nominally set in Massachusetts. Starring Cillian Murphy, Armie Hammer and Sharlto Copley, it was actually shot in Brighton at the old printing works for the Brighton Argus newspaper.

Director Ben Wheatley's new film 'Free Fire' is executively produced by his hero Martin Scorsese (Getty Images)

Scorsese never quite made it to the English south coast – but with his name on the credits, he kept an eye on the project. “We had to take it to him and show it to him, which was terrifying. But he loved it.” It’s yet another milestone in the Wheatley story; one of the few British filmmakers to break from the genre scene and penetrate the mainstream.

Sitting in London’s Corinthia Hotel, sniffing his way through a cold, the Billericay-born Wheatley may now be 44, but he hasn’t changed much since directing his debut feature, 2009’s unsettling crime story Down Terrace, in just eight days. He still lives in Brighton, where he and his wife and regular screenwriter Amy Jump raise their young son and run their company Rook Films.

Wheatley, who studied for a degree in fine art sculpture before posting short films online led him to TV and commercial work, has very carefully managed his growth as a filmmaker. After Kill List, he’d eschewed the more “technical and difficult” scripts he’d readied if favour of the “purely performance”-based Sightseers, a comedy about a serial killers couple holidaying in England.

Jack Reynor as Harry, Sharlto Copley as Vern and Armie Hammer as Ord in 'Free Fire' (Kerry Brown ) (Kerry Brown)

Free Fire may have Scorsese on board and a cast that includes Oscar-winner Brie Larson, but Wheatley has similarly managed to keep it contained. There was no need to travel to America to shoot it, not when Shoreham Docks can double as a port-side location. The production even found an abandoned Gran Torino car close by. “We looked at it and it had tax discs in it from New York 1974,” he laughs. Fate has a funny way of intervening.

While some will cite Quentin Tarantino’s crooks-in-warehouse debut Reservoir Dogs as the obvious influence on Free Fire, Wheatley was looking back further, to 1970s gritty crime sagas like Who’ll Stop The Rain, The Friends of Eddie Coyle and Straight Time, not to mention Scorsese’s own Mean Streets, albeit filtered through his and Jump’s sensibilities, as bullets and barbs are exchanged with increasing rapidity.

The story is a bloody game of survival after an arms deal goes wrong, leading to the mother of all Mexican stand-offs. If the shootout is a tradition of the crime film, Free Fire is that moment “taken to the nth degree”, says Wheatley. “I’ve always wanted to do a more action-based movie. A genre movie with a big ‘G’. The other genre films we’ve done have been a step to the left or the right of genre. So I wanted to make something that was more straight ahead.”

Brie Larson as Justine and Cillian Murphy as Chris in 'Free Fire' (Kerry Brown ) (Kerry Brown)

His idea was to make something about real people under real pressure in real jeopardy. “It wasn’t about superheroes blowing up planets and cities dissolving.” In one scene, two wounded characters desperately slither towards the only phone in the building – this is pre-mobiles, remember – to call in back-up. “Crawling up a flight of stairs is one of the big action sequences in the film!” he says. It’s painful. It’s funny. It’s very Ben Wheatley.

Despite primarily being set in one location, Free Fire was a huge logistical challenge. Wheatley designed the entire set in 3D in the video game Minecraft, before using storyboards and models to plan out precisely the movements of each character around the set. “It’s not something you can make up on the day,” he says, pointing out that for every wall being hit by a bullet (and there are lots of them), a fake panel must be created to ‘explode’ dust from.

Still, there will come a time when Wheatley takes these skills into a bigger arena, in the way Gareth Edwards did on Godzilla and Rogue One. There’s certainly no shortage of material. He and Jump make it a policy to write other films while one is in production. “So for every film we’ve made, we’ve probably written three or four scripts. And over time they all start to stack up.”

Among those in the pile are Freakshift, a film Wheatley has had in his locker since Kill List which he describes “policeman versus monsters”. Set to shoot in August, Alicia Vikander is currently in talks. Then there’s Hard Boiled, a take on Frank Miller’s early-’90s comic-book series, in which his High-Rise star Tom Hiddleston will play a tax collector in a dystopian Los Angeles.

“I don’t want to get into that cycle of four years, five years, then suddenly it’s one [movie made] every six years, which seems to happen to a lot of people,” he says. It’s not just the writing where Wheatley is smartly thinking ahead. A former storyboard artist, he’s started to art-design projects in advance, rather than wait for financing and rush the design phase in pre-production. “I want to have them prepped before that moment.”

Comparable to Guillermo del Toro, who began on small-scale genre productions like Cronos, could he similarly go and work in America? “If Free Fire had been set outdoors in a town, we’d have gone to America to shoot it,” he shrugs. But there’s something perfect right now about his set-up. “While I’m making films produced by my own company, it’s much more comfortable for me. Also, it’s nice making stuff near your house! You don’t have to move around!”