When he came from his native Brasso (no, really) in Transylvania to Paris in the 1920s, the photographer Gyula Halasz, better known as Brassa∩, lived by night, "going to bed at sunrise, getting up at sunset, wandering about the city from Montparnasse to Montmartre".

Along with other well-known nightwalkers - Henry Miller, LΘon-Paul Fargue, Raymond Queneau, Jacques PrΘvert, he would pass the hours of darkness prowling the lower depths, revelling in the "beauty of sinister things", as PrΘvert put it.

Brassa∩ was fascinated by the world of the night " day"s negative, so to speak - especially among the shadier sorts, the thieves and tarts, the pimps, the small-time gangsters, the indefininable "shady young men", but also among the workers, such as repairers of streetcar tracks, the cesspool cleaners, the porters and vendors in the vegetable markets, the butchers of La Villette.

"Rightly or wrongly, I felt at the time that this underground world represented Paris at its least cosmopolitan, at its most alive, its most authentic, that in these colourful faces of its underworld there had been preserved, from age to age, almost without alteration, the folklore of its most remote past."

In his first years in Paris Brassa∩ worked as a journalist, and only developed an interest in photography out of a desire to preserve the images of a world that was already beginning to disappear. Gradually he made his way from the nocturnal streets into the interiors, of criminal bars, of brothels and gambling houses, gay clubs, opium dens, urinals, even. The Secret Paris of the 30's, first published in 1976 and now reissued, is his extraordinarily evocative record of this prewar city of night.

These are not pretty pictures, nor are they "artistic" in the usual sense. One does not go to Brassa∩ for beauty of image or for consummate technique, as one goes to Cartier-Bresson, for instance, or Bourbat; Brassa∩'s work is to theirs as the novels of CΘline are to those of Saint-ExupΘry.

It is a rough, tough and exploitative world that is captured by these pictures, and by Brassa∩'s wonderfully pungent text.

This is not the naughty Paris of the smirking operettas, but the city of Dostoevsky's Underground Man, where all that is on offer is, as the photographer puts it, "the beauty of evil, the magic of the lower depths".

John Banville is Associate Literary Editor and Chief Literary Critic of The Irish Times