"Investigation of a Citizen Above Suspicion" is a provocative political thriller that is as troubling today as when it came out in 1970. Maybe more so.

Directed by Italy's Elio Petri and winner of the Oscar for best foreign-language film as well as a special jury prize at Cannes, "Investigation" did not please everyone on its initial American release. To the New York Times' Vincent Canby it was "a stunning movie," while the New Yorker's Pauline Kael called it "extremely dislikable."

With intelligent subtitles and a beautifully restored new print showing it to its best advantage during a one-week run at the Nuart in West Los Angeles, "Investigation" continues to be an intentionally unsettling film. It purposefully keeps us off balance thematically and stylistically from the opening notes of Ennio Morricone's dark, jangling score.

That music accompanies a man in a white suit (the mercurial Gian Maria Volonté) as he stealthily approaches the apartment of his beautiful mistress, Augusta (Florinda Bolkan).

This caution is not just because he's a surreptitious lover. The man, who we come to learn has engaged in a variety of kinky sex games with Augusta, this time plans for the violence to be real. He slits Augusta's throat, then calls the police to report the murder.

If that sounds like an unusual move, that's just the half of it. For not only does the man turn out to be a police inspector, he's also the crack chief of Rome's homicide department, a celebrity cop responsible for solving 90% of the city's murders.

Superbly played by Volonté, the inspector on the job is a picture of brazen confidence and bravado, strutting around like a miniature Mussolini and terrifying his subordinates with his unwavering belief that he is right about everything.

While the film's flashbacks gradually reveal some of the personal reasons for the inspector's bloody act, this study of sexual politics and the potency of power makes it inescapable that the man committed murder in part because he felt he could get away with it, felt his position insulated him from the consequences ordinary mortals would have to fear.

But because the inspector's thought processes are not particularly straightforward, even that is not the whole psychological story. On the one hand he takes the time to plant clues that implicate himself, daring his men to think he's guilty, but on the other he undermines the clues, trying to make them seem unimportant.

It's as if, and this is the heart of "Investigation's" fascination, the inspector can't decide whether he wants to get away with the crime to prove his privileged position, or wants to be caught to prove the superiority of the system of laws and punishments he has spent his life representing.

Adding a particularly contemporary wrinkle, the inspector commits the murder just as he is being promoted to head of political intelligence, charged with spying on and controlling various dissenting political groups, including communists, anarchists and Trotskyites.

In a savage speech that chillingly prefigures what some public figures are saying in defense of the Patriot Act, the inspector insists that there is no distinction between criminal and political acts, that "in every criminal a subversive may by hiding, and in every subversive a criminal may be hiding."

He is adamant that freedom breeds the terrors of anarchy and that repression is the most effective way to cure those society-threatening ills.

A committed Marxist, director Petri (who co-wrote the script with Ugo Pirro), intended "Investigation" to illustrate Franz Kafka's cryptic aphorism that "He is the servant of the law and eludes judgment." With a directing style as sharp as the crease in the inspector's pants, he's made a film that can disturb our rest, even decades after the fact.

'Investigation of a Citizen Above Suspicion'

Where: Landmark Nuart Theatre, 11272 Santa Monica Blvd., West L.A.

When: Today, Monday-Thursday, 4:30, 7:15 and 10 p.m.; Saturday and Sunday, 1:50, 4:30, 7:15 and 10 p.m.

Contact: (310) 281-8223

Running time: 1 hour, 52 minutes