When Dominique Strauss-Kahn was charged with sexual assault, he knew he could count on one ally - his formidable and well-connected wife.

On the first night of Dominique Strauss-Kahn's house arrest in New York, Anne Sinclair sent out for dinner. The couple were in a luxury Tribeca pad while he awaited trial on charges of sexual assault and the attempted rape of a hotel chambermaid. After Strauss-Kahn's sojourn in the notorious Rikers Island jail, the 63-year-old Sinclair was determined her husband should have some proper food.

So she telephoned the upmarket Landmarc bistro nearby and ordered £150 ($286) worth of steak and salads. It might be fair to assume that given the steely tenacity with which she has faced down the most tumultuous episode in her marriage, Sinclair probably wanted the steak bloody or, as the French would have it, saignant.

"She is a woman with a lot of character, a lot of force," says Renaud Revel, the author of a recent biography of Sinclair.

"She has an extremely resilient temperament. I have known her, on and off, for 25 years and I have a lot of respect and admiration for her. She's very loyal, very straight, she does what she says, she doesn't cheat."

Unlike, it seems, her errant husband.

For years, Strauss-Kahn, the former head of the International Monetary Fund, has been trailed by a swarm of women claiming to have been seduced by him.

In 2008, the socialist politician Aurelie Filipetti said Strauss-Kahn had made a "very heavy, very insistent" attempt to bed her.

Then there was a European journalist who claimed Strauss-Kahn would give her an interview only if she spent the weekend with him, and French writer Tristane Banon, whose legal complaint against him for attempted rape is still being investigated. Even his allies admit Strauss-Kahn is "le grand seducteur". Behind the scenes at the IMF there was concern his sexual predilections were, in the words of one former colleague, "an addiction".

Yet his wife has stood by him: a dignified, silent, supportive presence.

According to Revel, when her husband was arrested in May after a Guinean chambermaid working in the Sofitel New York hotel made an allegation of attempted rape, Sinclair was shopping for shoes on the rue Saint-Honore.

She received a call from her husband while getting ready for a friend's birthday party in which Strauss-Kahn spoke of a "serious problem".

Sinclair is said to have rung Stephane Fouks, the head of a publicity firm and a friend, for advice. But it was only when she was in a taxi, returning from the party at around midnight, that her phone rang again and she learned the nature of that "serious problem".

She stayed up until dawn, calling everyone she knew in New York to ensure top-level legal representation for her husband. Then she flew out to be with him and posted US$1 million ($1.17 million) bail in cash and a further US$5 million insurance bond.

She is said to have told friends: "Listen, I have maybe 20 years left to live. I want to live them by his side."

Last week, when prosecutors dropped all charges against Strauss-Kahn, the couple emerged from the courtroom to make their way through the waiting journalists. Sinclair, dressed in her trademark black, hair pushed neatly behind her ears, allowed herself a small but noticeable smile. As ever, she was standing by her man - to the bafflement of many.

"It's interesting because there is a cultural divide," says Agnes Poirier, a French cultural commentator.

"It looks quite Anglo-Saxon to say, 'My husband or wife cheated on me, I ask for a divorce.' For the French, it's a bit immature. If you love someone, you accept their weaknesses."

But surely, with Strauss-Kahn, it goes beyond an occasional weakness? "It's true that, as we say in France, she's had to 'swallow a lot of snakes' since being married to Dominique Strauss-Kahn."

Anne Sinclair was born Anne-Elise Schwartz in New York to French-Jewish parents who fled the Nazis during World War II.

The family, who later changed their name to Sinclair, returned to France in the 1950s and their daughter went on to study politics at the elite Sciences Po (Paris Institute of Political Studies) before graduating in law from the University of Paris.

Her first job was as a radio presenter for Europe 1, where she met and fell in love with Ivan Levai, the political chief of the station, whom she later married. In the 1970s, she moved into television, earning her stripes as an interviewer.

From 1984 to 1997, she hosted 7/7, a weekly political show that had one of the largest audiences in France. She interviewed Mikhail Gorbachev, Jacques Chirac, Bill Clinton, as well as Madonna and Sharon Stone. Sinclair became one of the most recognised journalists in France.

Sinclair met Strauss-Kahn, then the president of France's finance commission, when she interviewed him in 1989. Despite both being married, it was love at first sight.

The couple divorced their spouses and married in 1991. "There was an immediate closeness," Sinclair recalled in an interview with Paris Match. "It was like we'd come from the same village, as if we'd known each other always."

From the beginning, says Revel, Sinclair was "ambitious for him. She always considered his political destiny to be the Elysee". Before his arrest in New York, the French polls put Strauss-Kahn, who was about to declare his candidacy, 20 points ahead of Nicolas Sarkozy for the 2012 presidential election.

For the moment, that ambition has been put on hold. But it would be a mistake to undermine Sinclair's determination. Her support of Strauss-Kahn comes from loyalty and an ironclad conviction of the rightness of her actions and beliefs. If she ever decided to enter politics, she would be a real force to be reckoned with.

The Sinclair file
Born: Anne-Elise Schwartz in 1948, New York, to Joseph-Robert Schwartz and Micheline Nanette Rosenberg. She is also the granddaughter of Paul Rosenberg, one of France's biggest art dealers.

Best of times: Sinclair hosted one of France's most popular television programmes, 7/7, between 1984 and 1997. Her guests ranged from heads of state to celebrities. The show attracted between 10 to 12 million viewers a week in France.

Worst of times: Apart from the recent case, in 2008, her husband was forced to apologise and admit to a "serious error of judgment" after an affair with an IMF employee in Washington DC. Sinclair forgave her husband, stating: "These are things that can happen in any couple. For me, this one-night stand is behind us, we've turned the page. And we still love each other like on the first day."

She says: "I don't believe for a second the accusations of sexual assault by my husband."

They say: "In her heyday, most of France came to a halt on Sunday evenings to watch her perform and to see the sparkle in the eyes of ageing barons of French politics as they tripped over themselves to please her." Michael Johnson, American Spectator