The tobacco industry is one of the most greedy and deceptive there is. All its major companies have covered up official research which proves their products are disease-causing fire hazards, marketed them to underage kids, manipulated levels of nicotine to promote addiction and lied about these actions in open court. Everyone is disgusted at its behaviour -- onlookers, customers and even employees.

A case in point is Jeffrey Wigand, a former smoker who once headed the research department of Brown & Williamson, the third biggest cigarette manufacturer in the USA. B&W fired him for shooting off his mouth about company policy after his employers kept ignoring his evidence on how to produce a safer smoke. And then it went to great pains to destroy his life, when it became apparent that he intended to blow the whistle on its official secrets.

Michael Mann's "The Insider" stars Russell Crowe as Wigand, tells his story from the moment he was fired, and for the most part remains faithful to the facts. At the start of the film he is a man who does not want to rock the boat, despite his important knowledge about his bosses' dirty tricks. He usually speaks his mind, but breaking his confidentiality agreement with B&W would cut off his severance payments and medical insurance.

He denies an interview request from Lowell Bergman (Al Pacino), an investigative reporter for the television news magazine "60 Minutes". Until, that is, B&W send him uncalled-for violent reminders to keep quiet, which include a bullet in his mailbox, e-mail death threats and up-front stalkers. Then Wigand, furiously angry, agrees to record the interview, in which he reveals damning facts about the perjury and illegal cover-ups his firm was involved in.

CBS, the channel that runs "60 Minutes", decides not to broadcast the footage, because their executives have been threatened with a B&W lawsuit for "tortious interference". Bergman's fight against this decision is passionate, and takes up the second half of the film, but Wigand is offended that it was made in the first place. His involvement with Bergman has broken up his marriage, and provoked B&W to cancel his financial benefits and orchestrate a smear campaign against him. He starts to drink, shout, hate; in short, his life goes to hell.

But "The Insider" is not, as some reviews have stated, a character study of ambiguous American heroes. Nor does it make much of an impression as a tale of the struggles involved in investigative journalism. It involves both these things, yes, as well as elements of courtroom drama, but most critics are simply trying to find sophisticated ways of saying the movie isn't an attack on the tobacco industry, when that's exactly what it is. Every scene is haunted by the evil intimidation of Brown & Williamson: When Wigand's life is crumbling, when close relationships disintegrate, when Bergman's superiors are afraid to air his story, when court proceedings keep getting obstructed -- it's always obvious who's throwing the spanner in the works.

The news that big corporations use their influence destructively hardly surprises us (it's widely rumoured that the oil industry, for example, is just as bad as Big Tobacco). But we're still angered by it, and that's why "The Insider" works, unlike the Marie Brenner magazine article it's based on, which was interesting, but developed into a puzzle of facts and figures that was impossible to follow.

Mann, the director and co-writer, gets past this problem by organising the material in the manner of a slick Hollywood thriller. That's his forte -- he made "Thief", "Last of the Mohicans" and "Heat", all of which are acclaimed epic action pictures. Bergman's story, when told with their intensity and immediacy, becomes something we can easily get involved in. It's a pity that Mann is less interested by Wigand's (more attention-grabbing) plight. The developments in that character's life seem to be skimmed over in comparison to Bergman's; there's less of a structure to his tale.

Luckily, Russell Crowe gets across the point well enough with his startlingly brave acting. The physical side of his role involved putting on a dangerous amount of weight, wearing a grey wig and ageing make-up, and replacing his young Australian voice with the accent of a middle-aged man from Kentucky. Psychologically, he challenges us to admire Wigand's courage despite his bad temper, indecisiveness and shifty body language. Crowe always seems to be shaking a little, with eyes glaring and angry, and paranoid fingers fumbling -- but of course there's every justification for these nervous ticks.

This is great characterisation, and the way Crowe paints Wigand's breakdown incenses us at those who would seek to destroy his reputation. On that note, though, lies one of the significant problems I had with "The Insider", which is its unnecessarily dark portrayal of Mike Wallace, the presenter of "60 Minutes". I understand the need for screenwriters to take dramatic license when adapting true stories, or to condense events to make them cinematic. But Wallace, who in reality fought alongside Bergman, is shown bowing to CBS corporate pressure for no other reason than to make Al Pacino look more heroic. This is a film that wants to discuss the importance of truth. Lies and hypocrisy are not the best way to kick off the debate.