Juan Davila The Woomera Concentration Camp, South Australia, January 2002, 2001-2002, oil on canvas and cutout Perspex, 175 x 200 cm, courtesy Kalli Rolfe Contemporary Art, photo by Mark Ashkanasy.

Woomera in South Australia occupies a dire place in the cultural memory of this country. As the site of the notorious refugee detention centre, Woomera represents the poor calibre of antipodean compassion and expresses the widespread public inability to recognise the human needs of refugees. The harsh treatment of Afghani citizens communicates a national embarrassment to a global audience.

Juan Davila explores the notorious camp in graphically economical pictures. The paintings are not a documentary of how Woomera physically appears but a psychological rendering of how the camp operates in the imagination, in the minds of those inside, those who set it up, those who condone it and those who watch in horrified impotence.

The settlement is shown in a number of pictures as a scruffy sequence of shacks strung along the unshaded horizon. The landscape is desolate, peopled only with power poles. Any feature stands out with anomalous linearity.

In The Woomera Concentration Camp, South Australia, this barren scenery bisects the picture behind a group of interlocking figures. The foremost is a young woman of willowy aspect with a roll-neck jumper and trousers beneath her skirt. She looks at us while holding a paper in both hands. Behind her, a naked woman with masculine neck and jaw tenderly paws at her front, as if searching for the nipple; while other somnolent figures appear further behind and below. One grips a shoe, as if a phallic handle.

The sexual nature of this group is made clear by a male guard in the background - somewhat resembling the artist - who clutches at his groin and leers unwholesomely. The amalgam of figures, blended in space and gender, recalls the curious exchange of bodies and affection in Leonardo da Vinci's Burlington cartoon, in which Mary and Elizabeth seem to share a short supply of legs. Freud famously analysed this ambiguous picture as a cypher for the artist's unconscious melding of mother and other guardian.

Many of Davila's pictures are vituperative in a learned way. This is the case with Election. In one corner of this busy work, a grizzly Mr Howard draws a rickshaw with a lordly Osama Bin Laden in it, caricaturing old nationalistic racist posters that showed the Aussie as coolie, hauling his new Chinese master. The implication is that the Afghani refugees, if allowed into Australia with a profusion of Islamic identity, will very soon usurp the rightful superiority of the white middle class and sell our captains into slavery.

The angriest work is the Goyesque Detained, in which a cowboy (an armed politician) guards a shrieking victim as he or she is gnawed at by two dogs. A highly sardonic Adrift shows copulation in a tiny boat which moves toward a deserted shore, with ramshackle tumble-down building stock, maliciously resembling the gaggle of skew cubes that characterizes much of Melbourne's recent public architecture.

But for all this graphic ferocity, Davila emerges as compassionate, apparently using his own physiognomy for some stereotypical villains and insinuating a kind of sexual dependency that the authorities have upon the disempowered. It gratifies the keepers that they can control the sexual transactions of the captives. And up to a point, Davila shows that he can picture himself in this disgusting psychological predicament.

Davila does not preach. His story is complicated. A large work on vinyl, Self-Portrait, bears the words 'we offer no apology' in huge letters. This is presumably voiced by the robotic politicians on the right; but the same text appears on the bed of a naked male refugee with lips sewn up. The words, then, might also proceed from the speechless victim: he will not apologize for anything nor suddenly become agreeable or conciliatory. As a refugee he holds one element of power, the stubborn ownership of his own feelings. Davila paints the refugees as Europeans, not as a middle-eastern other.

Though numbered and dehumanised, the refugees are still conspicuously sexual, with eyes passively wandering but touched with lascivious torpor. In combinations of nakedness and intimate interaction they are bristling with urges - perhaps made neurotic by the terms of indefinite incarceration - but in all events enjoying a symbolic life. By contrast, the politicians are alienated from symbolic invention. They enjoy only the power to rehearse dim platitudes. They are automatons, guided mechanistically by their electoral chances.

In a sketchy cartoon-like style, Davila speaks for what happens in fact and what happens in the imagination. Davila is a good political artist because he does not just bring ridicule to anecdote but seeks the sexual economy that underlies power relations. He works through metaphors, hatching enigmas that chillingly point to the psychological causes of social brutality.

By blends of broad sympathy, ambiguity and psychoanalytical fantasy, Davila acquires a resonant social voice, fortunately resisting the new 'liberal paranoia' - as he calls it - by which the unethical is normalized.