The Japanese network Fuji Television and its parent company say its president and chairperson have resigned over a widening sex assault scandal involving one of Japan’s top TV celebrities

The spiralling controversy involves Masahiro Nakai, the 52-year-old media personality who was the leader of defunct male idol group Smap, and mainstream broadcaster Fuji Television. It also highlights the growing role that foreign activist shareholders are playing in compelling change in stuffy Japanese boardrooms.

The chairman and president of Japan’s Fuji Television resigned Monday, weeks after a celebrity presenter was accused of sexual assault, causing a public relations storm and the mass exit of advertisers.