IN the argot of Britain’s criminal brethren, “filth” is not merely dirt, grot and muck. It’s also the crims’ nickname for the cops.

Director Jon Baird with co-writer and novelist Irvine Welsh have confected a film in which comedy and drama jointly canvass a plethora of social and personal issues set in motion when a gang of Scots hoodlums kill a Japanese student. What they next see causes them immediately to flee. But we don’t get to see it.

James McAvoy plays Bruce, the DS assigned to track the hoodlums down. Bruce is host to just about every anxiety and social, chemical, hormonal, relational, behavioural issue that can beset any human. He’s desperate to mend fences with his missing wife and daughter. He needs the extra salary that promotion to DI will bring. Bruce is not lovable now nor will he ever be.

Less a crime thriller than a study of a man already promoted beyond his moral level, “Filth” leads us among the city’s human dregs as Bruce abuses the people he is questioning, copulates indiscriminately with whores and colleagues’ wives (one played by that marvellous pint-sized ball of fiery wickedness Shirley Henderson), betrays friends, snorts illicit substances and drinks on the job.

This catalogue of human inadequacies presents both sides of the “filth” synonym with a sense of uncompromising delight at being able to shine them on screen unrestrained by dramatic and moral precepts. Its funny is as much peculiar as ha-ha. McAvoy’s performance is a traffic stopper.

At Palace Electric, Greater Union and Dendy