The Informers, by Juan Gabriel Vásquez trans Anne McLean

A Colombian crusader lost in history's labyrinth

The Brad Pitt-Angelina Jolie caper Mr and Mrs Smith risibly portrayed Bogota as a sun-scorched tropical outpost. Thank you, Hollywood. Colombia's high-altitude capital is a huge, drizzly maze of a metropolis, flanked by its wall of wooded mountains, peopled (in the words of this book's narrator) by "grey faces" and plagued by "constant cold and rain". Readers from a landscape itself painted in shifting shades of green and grey should adjust easily to the overcast moral climate of an outstanding novel. The Colombian Juan Gabriel Vásquez, one of the most gifted writers to emerge from Latin America in recent years, fashions a misty and enigmatic mood of doubt, shadow and secrecy. His sombre city feels almost as if mature John Le Carré had wandered into the narrative labyrinths of Borges.

In the Bogota of the late 1980s and early 1990s, journalist Gabriel Santoro has published a book about a beloved family friend, Sara Guterman. She fled Nazi Germany as a teenager, and her parents became hotel-keepers in Colombia. Bizarrely, his father (also Gabriel), a famously incorruptible orator and teacher of public-speaking skills to lawyers, vehemently attacks his own son's book in a review. To his students, he denounces media parasites who steal other people's lives, "one of the lowest occupations in humanity".

Why has this well-meaning investigator's ever-so-correct book about a woman who escaped the Holocaust made him – in his father's view – into a bloodsucker, a traitor and, above all, an informer? Through a deft but never tricksy story-telling architecture of tales within tales, we return to the early 1940s.

Then, a single event shaped (and, so his son comes to suspect, wrecked) Santoro senior's life. We discover it, fragment by fragment, from young Gabriel's sleuthing and from his father's friends: a chorus of dissonant voices beautifully captured in Anne McLean's perfectly pitched translation.

It turns out that Santoro, the future icon of integrity in public life, took a role in the enforcement of wartime "blacklists". Under US pressure, this catalogue of enemy aliens condemned many Germans in Colombia to detention, ruin and stigma for unproven Nazi sympathies.

The novel's moral conundrums reveal its sure and subtle touch. Yes, Colombia did harbour plenty of grisly Fascists (we hear about some of them); but deference to the US also meant that a Liberal government and its supporters destroyed the lives of many innocent families. Personal and political motives for betrayal mingle through Gabriel's finely-drawn encounters with the elusive Sara, with his father's physiotherapist-turned-lover, Angelina, and – climactically – with the son of a blacklisted German businessman, who was driven to suicide.

At every stage, Gabriel junior learns harsh lessons. Via stomach-kicking shocks, they inform him about his father's hidden life and baffling death, about the quicksands of human memory, and how the inquisitorial "white knight of history" can, in other eyes, look like a grubby snitch.

While Vásquez unveils the perils of the 1940s, the deadly noises-off of Bogota in the 1990s – as drug cartels bomb shopping malls and a lover's death in gang crossfire counts as "the most normal thing in the world"– yoke brutality and betrayal in the past and present. Bogota today feels a far less "demented place" than the theatre of fear and blood Sara recalls. But layer upon layer of scars remain: a history of half-concealed wounds, exposed by this richly woven tissue of cruel truths and healing lies.