Former French First Lady Carla Bruni-Sarkozy is suspected of fraud and witness tampering.
She faces up to 20 years in prison on charges of funding her husband's 2007 presidential campaign.
Investigators believe that Libya may have provided funds for the campaign, the New York Post reports.
In October 2023, former President Nicolas Sarkozy was twice charged with collusion and witness tampering. Sarkozy denies all charges.
Carla Bruni was asked to appear in court in her husband's case.
She is also suspected of concealing evidence and aiding criminals.
The scandal also involves a prominent businesswoman and a Lebanese arms dealer.
The investigation began in 2013 after one of Gaddafi's sons accused Sarkozy of receiving money from his father.
Later, the Franco-Lebanese businessman Ziad Takieddine confirmed the transfer.
Carla Bruni married Sarkozy a year after he became president of France.
Now the Sarkozy couple faces serious charges.