Jeff Shell, the head of Comcast's vast entertainment and media business, NBCUniversal, is leaving his role immediately, the company said Sunday, after an investigation found that he had engaged in "inappropriate conduct."

Shell had worked at Comcast for 19 years. In a brief statement, he apologized for an "inappropriate relationship with a woman in the company," and said he was "truly sorry" for letting down colleagues.

Comcast's statement added that outside counsel had been hired to oversee the investigation into Shell's behavior following a complaint, but provided very few other details.

Comcast has not yet named a successor to Shell, and announced that NBCU's senior managers would now report directly into the president of the Comcast, Mike Cavanagh.

Cavanagh said he was "disappointed to share this news" in a separate statement signed by himself and Comcast CEO Brian L. Roberts, the son of the Philadelphia-based company's founder. "We built this company on a culture of integrity," Roberts and Cavanagh wrote, according to CBNC. "You should count on your leaders to create a safe and respectful workplace."

Shell took on the NBCU CEO position in January 2020, succeeding Steve Burke just weeks before the COVID-19 pandemic devastated large swathes of the company's revenues, across news programming, entertainment networks, movies, and theme parks.

He joined Comcast in 2004 from Fox's cable division, and served as head of international operations in London before also chairing the company's film and entertainment division. [Copyright 2023 NPR]