France's Bruni makes emotional defense of husband Sarkozy PARIS (Reuters) - Former French first lady Carla Bruni took up a passionate defense of her husband Nicolas Sarkozy on Wednesday, saying it was unthinkable he could have tricked an old lady out of millions of euros. In a blitz of interviews with French media, Bruni said a formal investigation of the ex-president opened last week for allegedly exploiting the mental frailty of 90-year-old L'Oreal heiress Liliane Bettencourt was causing her great pain. It's impossible to imagine that this man could have abused the frailty of a lady the age of his mother... It's unthinkable," Bruni told RTL radio in a shaky voice. Sarkozy, who retreated from front-line politics after losing his re-election bid last May, rejects accusations that he took advantage of Bettencourt, France's richest woman, in 2007 to raise funds for his first election campaign. He wrote on Facebook this week that the probe against him was "unfair and unfounded." The case could scupper any political comeback for Sarkozy, whose remains a popular figure for center-right voters and has said he would consider running for president again in 2017. His lawyer, Thierry Herzog, has said he would seek to have the case thrown out on grounds that the investigation conducted by judge Jean-Michel Gentil was biased against Sarkozy. Singer-songwriter and former model Bruni played a restrained role as first lady while Sarkozy was in power but has since returned to the media spotlight, performing last week at the ECHO Music Awards in Berlin. Her public defense of Sarkozy coincides with her promotion of a new album due for release on April 1. Bruni's 2008 marriage to Sarkozy after a whirlwind courtship irritated many French people who felt the high-profile romance blurred the lines between the president's private and public lives. Asked if she was tempted to fight back publicly against the accusations and "show her claws," Bruni said: "Yes, I want to but I don't dare. It is difficult for me to talk about this, it's painful for my family. Reporting by Nicholas Vinocur; Editing by Catherine Bremer and Toby Chopra