Former Suntory CEO Takeshi Niinami stepped down Tuesday as chair of Keizai Doyukai, a major business lobby, just weeks after the outspoken business leader was caught up in an investigation related to a shipment of illegal supplements.

The group, also known as the Japan Association of Corporate Executives, said its senior vice chairperson, Mutsuo Iwai, will be acting as the chairperson until a new leader is chosen.

“It's regrettable, as there were things that I wanted to do,” Niinami said during a news conference on Tuesday.