NEW YORK (Kyodo) -- A U.S. investment fund that holds shares in Japan's Fuji Media Holdings Inc. has issued a letter calling for the resignation of a top adviser as the company's subsidiary broadcaster faces scrutiny over its handling of a sexual misconduct scandal involving former popular TV host Masahiro Nakai.

In the letter dated Monday, Dalton Investments LLC called for Executive Managing Adviser Hisashi Hieda to step down as director, saying recent events have highlighted the dysfunctional governance of Japanese broadcasting giant Fuji Television Network Inc.

Dalton said in the letter, "Why has a single dictator been allowed to control this vast broadcasting group for nearly 40 years? It beggars belief!" referring to Hieda, who serves as managing adviser and director to both Fuji Media and Fuji TV.

On Tuesday, Hieda, who also chairs the Fujisankei Communications Group, declined to comment on his future but told Kyodo News that he was unaware of the letter from the U.S. investment fund, which holds more than 7 percent of Fuji Media's shares.

The letter comes amid a controversy over Nakai, best known as a member of the now-defunct pop group SMAP, who was accused of inappropriate behavior toward a woman in 2023. Fuji TV has faced criticism for its handling of the case despite being aware of the "trouble" between them.

Dalton previously issued letters demanding the establishment of a third-party committee to investigate the incident while requesting Fuji Media to implement necessary measures "to prevent the re-emergence of a similar dictator figure in the future."

The scandal has since led to the resignation of Fuji TV Chairman Shuji Kano and President Koichi Minato.