US author Jonathan Littell, 39, has won France's Goncourt literary prize for his controversial novel about the life of a fictional SS officer.
New York-born Littell grew up in France until the age of 18
Written in French, Les Bienveillantes is currently the number one bestseller in France, where Littell grew up.
The book is a first-person fictional account of an unrepentant SS officer as he recalls the extermination of the Jews in World War II.
It has been criticised in some quarters for being inaccurate.
"What interested me was to understand what led people to become torturers," Littell, who now lives in Spain, told Agence France Presse.
The Goncourt jury said Les Bienveillantes (The Kindly Ones) surpassed works by French authors, winning the panel's vote by 7-3.
The 900-page novel is being translated into English, for release in the US in 2008.
Bi-lingual Littell, the son of US journalist and author Robert Littell, is said to have written the book in French as a tribute to authors Stendhal and Flaubert.
It is his first novel, and was rejected by several publishers before being picked up. It has gone on to sell more than 200,000 copies.
But historian Peter Shoettler branded it a "strange, monstrous book" that failed to tell the true story of the Holocaust.