The former head of a French company at the center of a breast implant scandal affecting tens of thousands of women worldwide was arrested along with his former deputy Thursday in southeast France, officials said. Jean-Claude Mas, who founded and ran the now-defunct implant maker Poly Implant Prothese, was detained as part of a judicial investigation in the southeastern city of Marseille into manslaughter and involuntary injuries, an official said. A regional official said the company’s former No. 2 executive, Claude Couty, was also detained.