PARIS -- Coco Chanel: A fashion icon whose name has become shorthand for timeless French chic, a shrewd businesswoman who overcame a childhood of poverty to build a luxury supernova and ... a Nazi spy?

A new book by a Paris-based American historian suggests Chanel not only had a wartime affair with a German aristocrat and spy, but that she herself was also an agent of Germany's Abwehr military intelligence organization and an anti-Semite.

Doubts about Chanel's loyalties during World War II have long festered, but "Sleeping with the Enemy: Coco Chanel's Secret War" goes well beyond those previous allegations, citing as evidence documents culled from archives around the world.

The book, published in the U.S. on Tuesday, has ruffled feathers in France, where the luxury industry is a pillar of the economy and Chanel is widely regarded as the crowning jewel.

The House of Chanel was quick to react, saying in a statement that "more than 57 books have been written about Gabrielle Chanel. ... We would encourage you to consult some of the more serious ones."

Hal Vaughan, an 84-year-old World War II veteran and longtime journalist who wrote two other history books, said "Sleeping with the Enemy" is the fruit of more than four years of intense labor born out of an accidental find in France's national police archive.

"I was looking for something else and I come across this document saying 'Chanel is a Nazi agent, her number is blah, blah, blah and her pseudonym is Westminster,"' Vaughan said. "I look at this again and I say, 'What the hell is this?' I couldn't believe my eyes. Then I really started hunting through all of the archives, in the United States, in London, in Berlin and in Rome."

Born in 1883 in a hospice for the poor in western France, Gabrielle Chanel had remade herself into the famed couturiere Coco Chanel by the outbreak of World War II. During the conflict, she holed up with Baron Hans Gunther von Dincklage -- a German officer 12 years her junior -- in Paris' Ritz Hotel, then under Nazi control.

The book alleges that in 1940, Chanel was recruited into the Abwehr -- her nom de guerre borrowed from another of her lovers, the Duke of Westminster. A year later, she traveled to Spain on a spy mission -- on condition the Nazis release her nephew from an internment camp -- and later went to Berlin on the orders of a top SS general, the book says.

It also suggests that Chanel's alleged anti-Semitism pushed her to try to capitalize on laws allowing for the expropriation of Jewish property to wrest control of the Chanel perfume lines from the Wertheimer brothers, a Jewish family who'd helped make her Chanel No. 5 a worldwide best-seller.

The Chanel statement refuted the claim, although it added that company officials have yet to read the book and had only seen media excerpts.

"She would hardly have formed a relationship with the family" -- which currently owns the entire Chanel brand empire -- "or counted Jewish people among her close friends and professional partners," it says.

After the war, Chanel was arrested and released hours later, saved by "the intervention of her old friend Winston Churchill," the news release for the book said. She fled to Switzerland.

Asked why the book, which is chock-a-block with allegations of Chanel's shady dealings before, during and after the war, had turned up so much more dirt than the scores of previous biographies about the fashion icon, Vaughan had two explanations. Firstly, many of the documents he cited had only recently been declassified.

Secondly, he said, many people have a vested interest in protecting Chanel's aura of unsullied chic.

"A lot of people in this world don't want the iconic figure of Gabrielle Coco Chanel, one of France's great cultural idols, destroyed," said Vaughan. "This is definitely something that a lot of people would have preferred to put aside, to forget, to just go on selling Chanel scarves and jewelry."

Despite the doubts that have long lingered over Chanel's wartime doings, the multi-billion-dollar fashion brand that bears her name has sought to spotlight its founder. For the set of its last runway show -- the fall-winter 2011 haute couture collection in July -- the brand recreated a life-size version of Paris' tony Place Vendome, swapping the towering Napoleon statue for a sculpture of Coco Chanel in her iconic tweeds.

Asked whether he thought "Sleeping with the Enemy" would tarnish the brand's reputation or adversely affect sales, Vaughan snickered.

"There's an expression in French, which translates as 'the dogs bark and the caravans pass,' and that's exactly what's going to happen here with this book," he predicted. Karl Lagerfeld -- the brand's current designer whose ponytailed silhouette is almost as iconic as Chanel herself -- "is not going to let this thing drift off anywhere, and Chanel will be a name for the next, I don't know, hundred years."