French prosecutors have confirmed that they are conducting a preliminary investigation into whether the U.S. National Security Agency violated French law by secretly collecting personal data.

Responding to an inquiry from The Associated Press, Agnes Thibault-Lecuivre, spokeswoman for the Paris prosecutor, said Wednesday that an investigation was opened in July after two rights groups filed a lawsuit. The France-based International Federation for Human Rights and Human Rights League say that the surveillance, disclosed by NSA leaker Edward Snowden, would violate French privacy laws.

The preliminary investigation would not necessarily lead to any charges. Like many French judicial processes it was not publicly announced.

The rights groups’ case is one of a series of legal efforts around the world, including in the U.S. and Britain, to raise pressure on the U.S.

(AP)