PARIS (AP) — The Paris prosecutor's office has opened a preliminary inquiry into a statement by the sister of radical Islamist Mohamed Merah, who said she's "proud" of her brother, who killed seven people, including three Jewish children, in March.

A judicial official said Monday that the probe for "defense of terrorism" is aimed at establishing the conditions under which Souad Merah spoke. Her words, captured by a hidden camera, were aired this weekend in a TV documentary based on an account by Merah's oldest brother, Abdelghani. He claims the Merah children, of Algerian origin, were raised on anti-Semitism.

Interior Minister Manuel Valls denounced Souad Merah's words, saying they can only be seen as a defense of terrorism and of anti-Semitism.

Merah was killed in a standoff with police at his Toulouse apartment.