Carla Bruni-Sarkozy (R), singer and former French First Lady, arrives at her residence in Paris March 22, 2013. Former French President Nicolas Sarkozy was placed under formal investigation on Thursday for "abuse of weakness" in a 2007 party funding case involving elderly L'Oreal heiress Liliane Bettencourt, the public prosecutor said. REUTERS/Benoit Tessier (FRANCE - Tags: POLITICS CRIME LAW ENTERTAINMENT) less