Barbara Steele is often referred to as "Britain's first lady of horror" but it's not an accolade that gives her much pleasure. We meet in Neuchâtel, Switzerland, just before a screening of Mario Bava's wondrously baroque and gruesome Mask of Satan (1960), the film for which she will go down in movie history, primarily for the scene in which the beautiful witch she plays is killed by having a metal mask with sharpened spikes squashed into her face. Another regular association was with cheapo director Roger Corman, for whom she made a slew of movies including The Pit and the Pendulum and Caged Heat. Now that Corman is considered worthy of a documentary celebration, Corman's World: Exploits of a Hollywood Rebel, Steele has found herself back in the limelight.

I ask her why she thinks horror film-makers are so drawn to her and she laughs. "This is a nightmare. I've asked myself this a thousand times and I've given up the question because I've always felt there's some dreadful lurking guilty thing in me." But the Birkenhead-born Steele isn't your typical horror diva. A former student at the Chelsea Arts School and a one-time Rank contract starlet, she still gives the impression of being embarrassed about a movie career that has seen her work with directors from Federico Fellini to David Cronenberg, from Volker Schlöndorff to Jonathan Demme.

"It sort of fell on me," she says. During her art school days, she spent one summer at the Citizens theatre in Glasgow, painting sets for a production of Bell, Book and Candle. An actress fell sick. Steele was plucked from the wings to take her place and was promptly talent spotted by the Rank Organisation.

Even now, in her early 70s, Steele still has that uncanny, saturnine look and those piercing, deep-set eyes that made her such an unsettling screen presence. Her own account of her film career makes her sound more like a victim than a movie star. She was one of the last actresses Rank put under contract: ask her about her time at Pinewood and she reminisces about executives who "drank a staggering amount of Scotch at lunch". The studio felt, she says, like "one glamorous pub". She went to premieres on the arm of Terry-Thomas and wore expensive evening gowns. "But then you had your £10 a week salary and you were trying to rent a room."

Mario Bava spotted her picture in a magazine and recruited her to star in Mask of Satan. Steele found him to be "very internalised, very quiet". His subdued personality was, she says, very similar to Corman's. "So many of these people who are enthralled with the chaotic dark side all look like Jesuit priests."

Steele herself preferred the flamboyance of Fellini, with whom she worked on 8½. "He'd have a Sicilian psychic on the set who looked like Rasputin and who would break eggs into the glass. The psychic would look into the glass and say: 'You can't shoot today.' Meanwhile, there are a hundred people in fabulous white costumes and the producer is going berserk."

Steele says she is startled when fans come up to her to enthuse about her old movies. "It's amazing to me. Incomprehensible. They come up to you as if you made it last Tuesday and they're so thrilled. I can't understand it." She even says that she can't stand "gore movies", an irony given that she is guest of honour at the Neuchâtel Fantastic film festival, which is holding a special programme of – what else? - "gore cinema".

Strangely, though, by the time she comes on stage to introduce Mask of Satan, a transformation has come over Steele. She basks in the applause of young horror fans and speaks enthusiastically about a film she had been urging me not to bother with half an hour before. On screen, she has an extraordinary mercurial quality: an ability to convey utter rage and malice one moment and then to seem like the sweetest, kindest ingénue the next. You quickly understand just what Bava, Corman and co saw in her.

• Corman's World: Exploits of a Hollywood Rebel screens on 30 July in venues across the UK as part of the Screen Arts festival