Lawyers for Sarkozy could not be immediately reached for comment on the reports, which cited judicial sources.
Sarkozy is accused of "interfering with a witness" and "criminal association with a view to committing fraud", media said.
Sarkozy had been questioned by a judge since Tuesday as part of a probe launched in May 2021, after French-Lebanese businessman Ziad Takieddine retracted earlier statements about having delivered Libyan funds in France.
Sarkozy, who denies any wrongdoing, is suspected of complicity in moves to falsely exonerate him in the Libyan case, which will go to trial in early 2025.
(Reporting by Dominique Vidalon; Editing by Jon Boyle)
