A big hit in Mexico, Rigoberto Castañeda’s horror thriller KM31 centres on a young woman whose twin sister is in a coma following a road accident. Bathed in blue light, the film has more than a whiff of J-horror about it, and Catalina’s search for the truth inevitably leads to a spooky ghost child.

KM31 received its UK premiere at FrightFest in August on the same day as the Zombie Walk. When I arrived at the Odeon for the interview hordes of dazed zombies were still hanging around Leicester Square, blinking in the sun as though it hurt or crumpled on benches: the perfect setting for an interview with a director who is a horror fan through and through.

Virginie Sélavy: You’ve said before that KM31 was influenced by films such as The Shining, The Exorcist, The Others and The Ring. Out of all these it seems to me that The Ring is the most relevant comparison, and you seem to have been influenced a lot by Japanese horror in general.

Rigoberto Castañeda: Many people have said that but I started writing the script for KM31 about seven years before pre-production started, so way before The Ring came out. It’s based on a well-known Mexican legend. Five or six years after I wrote the script The Ring came out. I went to see it and I was crushed because I thought it was so similar! I was about to quit! The producers suggested some changes but I said, you know what, fuck it, this has happened a hundred times in the history of cinema. The thing is, now more than ever because of the Internet, everybody sees the same things so it’s natural to have the same ideas. So I decided not to do anything.

VS: You don’t mention any Mexican films or directors in your influences. Why is that? Were you not influenced by Mexican horror in any way, by directors like Taboada and Moctezuma?

RC: In a way I was. When I was little I would go to my best friend’s house and watch horror movies at the weekend. I was pretty young when I saw The Exorcist, Rosemary’s Baby, The Shining, and also the Taboada movies and Alucarda by Moctezuma, which shocked me. I was really traumatised by those films. When I started film school I tried to find them but when I saw them again, I was like, that’s not as scary as I remember! So they influenced me because of the memory of watching them as a kid but they didn’t influence me in a cinematic way. As a filmmaker I’m influenced by directors who are not horror directors, like Hitchcock or Kubrick or Kurosawa, all the classic directors.

VS: In recent years Guillermo del Toro has had a big impact on the horror genre. Has he influenced you in any way?

RC: He’s God! I love him. In film school everybody knew him. I wanted to do horror so the teachers said there’s one person in Guadalajara who also likes horror film, he’s a make-up artist, you should hire him. I wanted to work with him but by the time I was ready to make my first short film he was already working on his first feature

VS: Do you think del Toro’s success has made it easier to make horror films in Mexico?

RC: His first picture in Mexico was Cronos. It was successful but it wasn’t really a horror film, it was more of a fantasy tale with horror elements. There was a vampire in it but the film was more a romantic story about the transformation of the vampire. When Cronos came out, everybody was like, that’s it, we’re going to have horror cinema, but nothing came out of it. So no, it’s weird but it didn’t help. KM31 is actually the first feature since Cronos that really is a horror film. When I decided I wanted to make a horror film, I thought that it would be a big success because there hadn’t been a horror film in Mexico since the 70s and Mexicans love horror. It was like a big wide open space. Now there are several horror films being made.

VS: I’ve seen that several of Taboada’s films are being remade.

RC: Yes, two of them. That’s fantastic! I hope they’re good! Right now there are several things that are helping. One of them was KM31, it was a big success so it helped the genre a lot. And then, many different Mexican directors have been very successful internationally and that’s helped to show that in Mexico we can make good films. The Oscar nominations were on when we were making the film, and there were sixteen nominations for Mexicans, so that helped a lot. Mexican people go a lot more to the movies, it’s definitely growing. The Mexican film industry in general is healthy.

VS: Is there anything that makes your film specifically Mexican?

RC: It’s mostly the legend of La Llorona. If you’re Mexican you will have heard it at some point in your life from your mother or your grandmother or your aunt or somebody. Every young kid in Mexico knows that if you behave badly La Llorona will come for you – it’s very scary for a young kid! We never mention the character in the film but it’s not necessary. When KM31 was showing in Mexico I went to the cinema to see people’s reactions. When the main ghost appears at the end of the movie everybody got so scared and started shouting, ‘La Llorona! La Llorona!’ – it was a very emotional moment for everyone. That makes it a very Mexican film. But at the same time I think it’s a universal story: La Llorona is like a banshee; it shares things with the Bible, and with Jewish tales. I think everybody in the world can identify with this story.

VS: Why did you decide to take that legend as your point of departure?

RC: Actually, the point of departure was something else. I was listening to Mexico’s most famous radio programme, a horror show called ‘The Hairy Hand’. People call the programme and tell a horror story that’s happened to them. Everybody loves to listen to this show and to tell their horror story. It’s amazing. It’s so big that they’re now broadcasting in the US. The day I started writing the script I was listening to the show and a truck driver called and told a story about seeing a woman in the middle of the road who was clearly a ghost. He told it in such an incredibly dramatic way, I’ve still got goose-bumps just remembering it. It was fantastic, I was almost crying with fear. So I ran back to my desk and I wrote the first ten minutes of the movie – I never changed those pages. And then I thought this could be a fantasy story, the story of the crying woman. So while I was writing those ten pages, I was already thinking of the story of La Llorona.

VS: Where were the scenes on the road and in the forest filmed? How did you find those locations?

RC: I wanted to write the script in a special place. I went to the forest that is around Mexico City. There are people who live there, just like in the film, people who have houses almost in the middle of the woods. When I was little, my parents used to take me to the forest. There is an old Catholic convent there, with catacombs, so it was REALLY SCARY for a kid. I used to love to go there when I was little.

VS: On your own?

RC: Yes, on my own. (laughs) So I decided to go there and write. I went to the convent, I looked at the woods, and I wrote on my computer, sat on a rock, and I got this feeling of the woods. The highway is the actual highway. The river up there in the woods goes down to the city and as the city grew the river became the sewer system. So it’s based on something that is real and on the tales that people told me when we were doing the research. KM31 was invented by me, it’s not real. But what’s quite funny is that now in Mexico there are people who go to KM31 and record videos, searching for the ghost! (laughs) It’s turned into a real story in Mexico!

VS: The scene in the sewers is very atmospheric. Were they a set or do they actually exist?

RC: We were very lucky. In Mexico City, they close the sewer systems to do work on it for six months every seven years. We were lucky to be ready to film during those six months so we were able to go down into the sewer system and shoot there. Right now, it’s full of shit, literally. But it’s an amazing place. The final part in the sewer system, that was constructed on a stage.

VS: You’ve said before that you had the intention of writing a ‘commercial thriller’. How did you go about doing that?

RC: I’m a movie buff, I love going to the cinema. I enjoy art-house films but I’ve always gone to the movies for entertainment. That’s my education in film, watching movies at my friend’s house. So I try to make films that I would have enjoyed as a kid.

VS: Do you see yourself solely as a horror director? Would you like to direct other types of movies or are you happy to keep exploring the horror genre?

RC: I think I will make horror films all my life. I’m interested in other genres but what I love is horror, thriller and fantasy, and I’d like to work in those three genres all my life. Fantasy is the most difficult of them because it’s the most expensive, so the way to get to fantasy is by starting with horror and thriller. It’s a way to get to fantasy but it doesn’t mean that they’re inferior genres. I see myself at 92, directing a horror film, (squeaky voice) ‘blood! more blood!’ I will never do romantic comedies. Never! (laughs)