David Cronenberg's 'Eastern Promises' shows a gritty, violent London. If only more films did the same

There are many ways of showing London on screen. Often, filmmakers depict the city from a tourist-eye view. Endless romantic comedies have name-checked notable landmarks while showing shiny double-decker buses and friendly policemen. The ghost of Stanley Holloway never seems far away. There is a self-conscious attempt to show off the city in the best possible light, regardless of the type of film being made. London now has its own agency – Film London – which prides itself on helping film-makers use such locations as the Houses of Parliament (V For Vendetta), Tate Modern (Children of Men) or Hyde Park (Stormbreaker).

The city has a chameleon-like ability to shift shapes. "You want 18th century, you want medieval or you want 21st century flash – it's all here within a couple of miles," Film London's boss Adrian Wootton recently boasted. But all too frequently, the London that appears on screen seems unreal or stuck in time.

You don't much associate London with film noir. From The Long Good Friday to Lock, Stock And Two Smoking Barrels, there have been plenty of gangster films made in the city, but only rarely have film-makers delved into what the critic Robert Warshow called "the dangerous and sad city of the imagination".

Audiences will shortly have the chance to see two brilliant films, both made by North American directors, which explore the seedy underbelly of London in a poetic and atmospheric way. The first, David Cronenberg's Eastern Promises, is about Russian gangsters on the prowl through the city. The London it depicts is unremittingly grey. Scripted by Steve Knight (who also wrote Stephen Frears' Dirty, Pretty Things), it is a film about outsiders. None of the main characters are Londoners. The lead characters are assassins, like the mysterious and ruthless Nikolai (Viggo Mortensen), or girls sold into the sex trade, or Chechen thugs. Even the heroine, played by Naomi Watts, is from a Russian background.

After Alexander Litvinenko, Eastern Promises has a topical resonance. The idea of killings taking place in broad daylight (for instance, the young Chelsea fan in the film who has his throat slit outside Stamford Bridge) no longer seems fanciful. Even so, this is as much a mood piece as it is a thriller. For all its extreme violence it's as much about bereavement, loss of identity and family ties in a strange city as it is about infiltrating the Russian mob.

Eastern Promises offers a more "realistic" portrait of London than that found all those romantic comedies about Notting Hill booksellers or lovelorn singletons. Using what film-makers call "creative geography", Cronenber g has taken just as many liberties with his locations – the difference is that his sensibility is so much darker. Shooting at Three Mills Studios in the heart of the East End, choosing locations like Smithfield, using Turkish baths rather than well-known tourist sites, he depicts a London that has a brooding sense of menace. The Thames looks filthy, and its main use for the Russians is as a place to toss corpses.

London is shown in an equally forlorn light in Jules Dassin's Night and the City (1950), which portrays a post-war London in the grip of hoodlums and racketeers. Thanks to the Blitz, there is rubble all over the place. Dassin throws in several sequences in which his lead character, the small-time US nightclub tout and would-be wrestling promoter Harry Fabian (Richard Widmark) is seen scurrying like a beetle across grey, decaying cityscapes with heavies in pursuit. Again, the Thames is where the bodies are dumped.

Dassin – who knew he was on the verge of being blacklisted in Hollywood because of his Communist associations – made the movie at a ferocious pace. In interviews, he has talked about the outrage and disbelief that it provoked in Britain. The UK press refused to believe that his London had any basis in reality. Dassin, who had researched the film meticulously, was amused by their scepticism. A Scotland Yard officer had taken him to all the most squalid dives in Soho and introduced him to the chancers and low-lifes upon whom he based his characters. "The British press didn't treat this film kindly, saying that this London of mine – I had made it up!" Dassin recalled. "Well, everything that was in the film was shot there. I invented nothing."

Back in the late 1940s and early 1950s, the British liked to think that their gangsters were less ferocious than their US counterparts. British police didn't carry guns. When PC Dixon (Jack Warner) was gunned down by Dirk Bogarde's young spiv Tom Riley in The Blue Lamp (1950), it was portrayed as a one-off act of unspeakable violence. The criminals were so appalled that they helped flush Riley out. In fact, as Night and the City showed, there never really was a golden age in which cops and thieves shared some secret code of honour.

It is surprising how few films over the years have shown this other side of London life. Wootton, who is director of London's Crime Scene Film Festival as well as the boss of Film London, argues that it takes outsiders to expose this hidden side of the city.

Night and the City and Eastern Promises are not unique. Periodically, other film-makers have also tried to bring noir to London. There have been such B-movies as John Lemont's The Frightened City (1961), starring Herbert Lom and a youthful, pre-Bond Sean Connery, which deals with protection racketeers in the West End, and Street Of Shadows (1953), featuring Cesar Romero as a nightclub owner.

Neil Jordan's Mona Lisa (1986) likewise shows the squalor and pathos of a London underworld where – as in Eastern Promises – young, drug-addicted women are forced into prostitution. Further back in time, films like EA Dupont's Piccadilly (1929), didn't shirk from showing racism and sexual violence, while the original version of They Drive By Night (1938) evoked a world of tawdry glamour and brutality.

New York's murky alleyways and LA's seedy glamour, have always lent themselves to film noir more readily than London. In recent years, we have become accustomed to London-set rom-coms, period dramas or sci-fi films that use the city in a predictable way. That's why Eastern Promises and the re-release of Night and the City are so refreshing.

Eastern Promises opens the the 51st Times BFI London Film Festival on 17 October prior to its UK release on 26 October. Night and the City is available on DVD as part of the BFI's Film Noir collection