Jeff Shell, the CEO of NBCUniversal, will step down «effective immediately,» according to a statement issued by Comcast Corporation on Sunday.

Comcast made the announcement Sunday afternoon following an «investigation led by outside counsel into an allegation of misconduct,» the statement said.

“We are disappointed to share this news with you,” read the statement issued by Brian L. Roberts and Mike Cavanaugh, Comcast CEO and Chairman, respectively. “We built this company on a culture of integrity. Nothing is more important than how we treat each other. You must count on your leaders to create a safe and respectful workplace. When our principles and policies are violated, we will always move quickly to take appropriate action, as we have done here.»

Jeff Shell in Los Angeles in 2019.Rob Latour/Variety via Getty Images File

Comcast did not clarify how Shell violated company policy, but in a statement, the former NBCUniversal chief executive said he had «an inappropriate relationship with a woman at the company.»

«Today is my last day as CEO of NBCUniversal,» Shell said. «I had an inappropriate relationship with a woman at the company, which I deeply regret. I am truly sorry for letting my colleagues at Comcast and NBCUniversal down.»

Shell was named CEO of NBCUniversal in January 2020. Previously, Shell was President of NBCUniversal Film and Entertainment.

Comcast owns NBCUniversal, which is the parent company of NBC News.

Ali Gostanian contributed.