"The amount of violence that I got into Hostel: Part II I don't think has been allowed in an American film before." Considering that this is the sequel to his hit 2005 horror Hostel, arguably the most violent film ever to be released by a Hollywood studio, then that's quite a feat. Then again, Roth . . .

right now the sickest man in cinema . . . is all about excess. "I think what attracts people to my films is that they feel I'm the guy who's not going to hold back on the scares and the violence, " he grins.

The original Hostel, with its story of three American male backpackers who head to Slovakia only to get lured to a warehouse where wealthy clients pay to torture their luckless victims, was "specifically about American arrogance" and "fear of other cultures", according to Roth. Or, if you prefer, it was simply about trying to cram as much gore into a feature film as possible. One scene features a woman whose face is set upon with a blowtorch until her eye pops; Roth calls it the "eyegasm" moment. "The goal is to build the scariest rollercoaster in the park, " he says. "You want to go on the one where people say: 'Don't go on that one. That's the one that will make you puke!'" Right now, extreme violence sells. Roth's 2003 debut feature Cabin Fever, which deals with a group of teenagers set upon by a flesh-eating virus, and Hostel, were made for less than $6m in total; together, they have grossed more than $100m worldwide.

From other directors, the three Saw films . . . all based around a fiendish psychotic killer named Jigsaw who incarcerates his victims in fiendish and deadly traps . . . have collectively taken more than $400m across the globe. Similar successes include the Outback psycho-horror Wolf Creek and the Texas-set The Devil's Rejects. Horror fans have already christened the directors of these films, including Roth, the Splat Pack.

It was The Devil's Rejects, directed by the former heavy metal musician Rob Zombie in 2005, that Roth believes opened the door for Hostel. This was a sequel to Zombie's earlier work, House of 1000 Corpses, about a Texas Chainsaw Massacre-style family of psychotic rural misfits.

Zombie found himself in a protracted battle with the US ratings board, the Motion Picture Association of America (MPAA). Forced to return there on nine separate occasions, each time with a different cut that he hoped would earn the acceptable "R" rating, he eventually wore down the censors. Roth feels they had little energy left to battle another director.

Since then, the 35-year-old has 17/06/07 become the unofficial leader of the Splat Pack - although, not surprisingly, Quentin Tarantino has become the godfather of the group of gore-hounds. After seeing Cabin Fever, Tarantino . . .

who calls Roth "the future of horror" . . . offered to help out on Hostel, lending his name to the production . . . hence the 'Quentin Tarantino Presents' banner that opens the film and its sequel.

Also credited as executive producer, Tarantino certainly comes on like an older brother to Roth. Both talk fast, are obsessive movie geeks, and regularly get together at Tarantino's pad in the Hollywood Hills to screen prints of obscure cult films. The only difference would seem to be their backgrounds. While Tarantino cut his teeth working at a video store, Roth worked his way into the film industry by a more traditional route. Raised in a stable, supportive environment - his father is a psychoanalyst, his mother an artist . . . he began making Super-8 short films with his friends when he was eight. He later went to New York University film school and then worked in just about every job a movie set has to offer, from stand-in to assistant editor. After heading to LA in 1999, he developed two separate animated series, Chowdaheads and The Rotten Fruit, and befriended the film-maker David Lynch.

Mentors Lynch was Roth's first mentor, but Tarantino has taken over that role, even casting Roth in the forthcoming Death Proof.

Roth also designed the fake trailer 'Thanksgiving' for Grindhouse - the double-bill of Death Proof and Robert Rodriguez's zombie movie Planet Terror that flopped in the States when it opened in April. It depicts a girl on a trampoline who winds up getting knifed as she does the splits.

"The style of violence I go for is very realistic, " says Roth. "Even in the Sawmovies, there's still an element of fantasy in those films . . . a killer setting traps; it's scary and it's fun. But the thing about Hostel is that it's made in a much more realistic, 'this could happen to you' way." Hostel: Part II continues this, beginning immediately where its predecessor leaves off; only this time it's college-age females (Bijou Phillips, Heather Matarazzo and Lauren German) who get to play the tortured travellers. One of the most gruesome scenes in the film, says Roth, involves the demise of Matarazzo. Strung upside down, naked, she is cut to ribbons with a scythe. While Lorna's torturer in the film is a woman, it is Roth who actually holds the blade to his victim. He and Tarantino get off on it in a rather creepy way.

"Quentin watched the scene, and said: 'I feel guilty saying this, but Heather Matarazzo is hot!'" Arguably, the work of Japanese auteur Miike Takashi (Audition) and Korean director Park Chanwook (Sympathy For Mr.

Vengeance) is far more excessive than anything Roth has done, but Hostel entered the mainstream culture in a way that Roth's Asian counterparts could only dream about, and its sequel is set to do the same.

Reflecting society Roth claims that he's doing nothing more than reflecting American society today - in particular the "horrifying, random outbreaks of violence" that the United States has become prone to. "People are specifically afraid of that person who has never done anything wrong: it's that person who stands next to you in church, the person that coaches Little League, or the person next to you in the supermarket."

If you bring out the age-old argument that such films inspire copycat violence, Roth has his answer well rehearsed. "There has been violence long before cinema has ever existed, " he says. "In medieval Europe, 300,000 people were tortured to death for being witches. If you blame a horror movie, it takes responsibility off yourself, or off the parents, for having to explain to their child the difference between real-life violence and movie violence."

Tarantino's Reservoir Dogs came out during the aftermath of the first Gulf War . . . and Roth argues that Hostel and its sequel are reflections of the more recent conflict there. "I get letters from soldiers in Iraq all the time who tell me how popular Hostel is on military bases, " he says. "When they're going out there on the battlefield, they have to be a machine. They're seeing people getting their faces blown off and kids getting killed, and they can't emotionally respond to this situation. Well, that gets stored up and there's no place to let it out. And when they show Hostel to 400 people, they're all screaming like little girls. They tell me that."

According to Roth, in America sitting in the dark watching a horror movie is the only place where it's "socially acceptable" to be scared. He claims that, "the people that go to see Hostel, I believe, find it very therapeutic."

But cathartic is one thing Hostel and its sequel are not; if anything, they simply turn violence into a vicarious and visceral pleasure, a ringside spectacle for anyone who dares to look. Not that this matters to Roth. He is already planning his next film (with the horror master Stephen King). And as long as he keeps making inexpensive movies that gross millions, studios will keep him around.

Money always comes before morals in Hollywood.

Hostel: Part II is released on 29 June