A journalist's account of life inside Baghdad's posh Green Zone enclave has won Great Britain's richest literary prize for non-fiction.

Washington Post journalist Rajiv Chandrasekaran's Imperial Life in the Emerald City was named winner of the £30,000 (nearly $64,000 Cdn) Samuel Johnson Prize at a ceremony at London's Savoy Hotel on Monday.

In the book, Chandrasekaran — the Post's Baghdad bureau chief from April 2003 to October 2004 — recounts stories of waste and incompetence within the city's heavily fortified Green Zone, which he depicts as strangely cut off from the chaos that reigns outside its walls.

Jury chair and human rights lawyer Helena Kennedy described Imperial Life in the Emerald City as "up there with the greatest reportage of the last 50 years — as fine as Hershey on Hiroshima and Capote's In Cold Blood."

Kennedy also praised the U.S. journalist's prose as "cool, exact and never overstated" and praised him for standing back, "detached and collected, from his subject."

Named in honour of the critic, essayist, poet and biographer, the Samuel Johnson Prize is in its ninth year of honouring non-fiction titles published in English in the U.K. Writers of any nationality are eligible for the annual honour.

Past winners include Margaret Macmillan for Peacemakers: The Paris Peace Conference of 1919, James Shapiro for 1599: A Year in the Life of William Shakespeare and T.J. Binyon for Pushkin: A biography.

With files from the Associated Press