In Spain, Eduardo Noriega has become the star of choice for some of the country's top directors. He tells Michael Dwyer about playing a daring ETA infiltrator in the thriller El Lobo, a smash hit at home.

THE hottest actor to emerge from Spain since Antonio Banderas and Javier Bardem, Eduardo Noriega was playing leading roles in movies within a year of graduating as a drama student in Madrid. In 1995, when he was 21, he acted in a short film for writer-director Alejandro Amenábar, who offered him a key role in his first feature film, the imaginative thriller Tesis (Thesis), in which a student finds a snuff movie in her college's archive.

"That film was like an explosion," Noriega said when we talked at the Dublin International Film Festival earlier this year. "It was a great success, and not only in Spain. Alejandro is a genius. He did almost everything. He was the scriptwriter, the producer, the director, the editor and he composed the music. And he was only 22 years old. He had fantastic ideas for someone so young."

In Amenábar's even more impressive second feature, the complex psychological thriller Abra los Ojos (Open Your Eyes), Noriega played the pivotal role of a handsome young man severely disfigured in an accident. Tom Cruise bought the remake rights and starred in the US version, Vanilla Sky, but the qualities of the original were lost in translation.

"I didn't like that version," Noriega says. "They had a problem. They really liked Abra los Ojos, but they didn't work out what they wanted to do with it. They just copied the original film. Shot by shot, it was the same, but empty. Having a lot of money to make a film isn't enough when you've nothing to say."

His performances in the two Amenábar films put Noriega on the map, and he has featured in 20 movies in the nine years since then. He was particularly impressive as the sinister, enigmatic young caretaker in Guillermo del Toro's eerie Spanish civil war ghost story, The Devil's Backbone.

"Del Toro is a great director for creating a unique atmosphere in his films," Noriega says. "He loves working with actors, so it's a pleasure to work with him. My character was very interesting because he was like a wounded animal that was so aggressive and so evil."

By contrast, Noriega demonstrated a deft lightness of touch in Novo, as a man with a memory disorder that makes him especially appealing to women because every time he has sex, it seems like the first time to him.

"It was like Memento, but French, and mixed with Nouvelle Vague and sex," Noriega laughs. "It was my first film in French, and I couldn't speak the language before then. I liked the director, Jean-Pierre Limosin. He is very shy. I think he has a communication problem in real life and that he finds it easier to communicate through the films he makes."

More recently, Noriega has had his biggest hit to date with El Lobo (The Wolf), a taut, factually-based thriller set in the mid-1970s. He plays a Basque construction worker man recruited by Franco's secret service to infiltrate ETA. His code name was Lobo.

"It's a very exciting story of a man caught between two dangerous worlds," Noriega says. "I could not believe it was a true story, that this man spent two years undercover with ETA. There were many fascinating things about him. When he was sleeping on the floor of a house with 12 or 13 terrorists, he could not sleep because he was scared of dreaming aloud and saying something in his sleep that could give him away. How can you live like that? What he did was incredible, giving up his identity, leaving his wife and family to protect them."

Noriega says that the film's executive producer, former journalist Melchor Miralles, received death threats when he was setting up the movie. "It was very brave of him to make the film for many reasons. If I had young children, as he does, I would have abandoned the film right away. It wouldn't be worth the risk. I'm not that much of a patriot."

Before the film started shooting, Miralles asked Noriega if he would like to meet the real Lobo. "I felt that was unnecessary at the time because Lobo today is so different from that naive young guy who started working with the police just to resolve a personal problem. From what I've heard, he has a very different view of himself and the world now. Now he thinks of himself as a hero who could have saved Spain from terrorism, but his attitude was very different at the time.

"When the film was finished and we were showing it to journalists in Madrid for the first time, the producer told me, 'Lobo is here', which was a dangerous thing for Lobo to do because so many journalists were there that day. Lobo was just so excited about meeting the actors. He told me he was much stronger than I was, and that one of the actresses in the film was not as attractive as the women in his life. I thought I was going to have this really deep conversation with him about terrorism, and this was all he wanted to talk about. He was as thrilled as a little boy that his story would be shown to the world in a film."

Having spent years in South America and after getting plastic surgery to disguise his features, Lobo has returned to live in Spain. "He tells wonderful stories, although I don't know if they are part of reality or myth. He told me that when he came back from South America, he felt very uncomfortable in Spain because ETA could be behind him at any time.

"So what does he do? He goes to the Basque country just to be sure that he won't be recognised. He says he was in a bar there when somebody bumped into him by mistake. He turned around and saw that it was the man who led ETA when he was undercover with them. He said he felt a few seconds of complete fear, and then the ETA man just apologised for bumping into him. After that he felt he could live in peace because nobody would recognise him. But I think he is still completely paranoid after living for 30 years with the thought that someone was out to kill him."

Of all the indigenous productions released in Spain last year, only Amenábar's The Sea Inside fared better than El Lobo at the box-office.

"That made Lobo very happy," Noriega says, "because he couldn't show his own face for years, but the film told his story to so many people. I was surprised the film was so successful, because most of the earlier films about ETA did not do well in Spain. The film reached a wider audience than any of my films. It got massive support from the newspaper El Mundo, which was important because when you've got that behind you, it makes it easier."

Noriega recently completed his first film in English, Che Guevara, in which he plays the title role for director Josh Evans, the son of Ali McGraw and Robert Evans. And he has enjoyed another hit in Spain with El Método, his second film for Argentinian director Marcelo Piñeyro after Burnt Money (2000) in which Noriega played one of two gay criminal lovers meeting a bullet-riddled fate in Uruguay.

In contrast to the physically demanding action of that movie, El Método takes place almost entirely inside a locked office. It plays sadistically with the minds of seven highly competitive applicants for a high-level post at a multinational corporation in Madrid, as they are put through an elimination process that is much nastier than anything in Big Brother.

"That was a new experience, sitting in this room with the other actors and four high-definition cameras rolling all the time," Noriega says. "You never knew when a camera was on you at any stage, so you could never relax, just like the characters in the film.

"On every other film I've made, you spend most of the day relaxing while they are setting up scenes and then you just have to concentrate very intensely for a specific time when you're shooting. El Método was the opposite, and we shot it chronologically. Piñeyro could have changed the script at any stage, which made us feel even more like the characters we were playing."

El Lobo opens in Dublin next Friday