Fox Sports fired Jamie Horowitz, its president of national networks, on Monday, according to a memo sent to employees, which provided no reasons for the dismissal but did emphasize the importance of “professional conduct.”

Horowitz’s departure comes amid allegations of sexual harassment, according to reports by The New York Times and The Los Angeles Times. Reuters could not independently verify those allegations.

Horowitz’s attorney, Patricia Glaser, a partner with Glaser Weil, called Fox’s treatment of Horowitz “appalling.”

“At no point in his tenure was there any mention by his superiors or human resources of any misconduct or an inability to adhere to professional conduct,” Glaser said in a statement. “Any slanderous accusations to the contrary will be vigorously defended.”

A spokeswoman for Fox Sports, part of Twenty-First Century Fox Inc (FOXA.O), declined to comment further on Horowitz’s departure, which was effective immediately.

Daniel Petrocelli, an attorney with O’Melveny & Myers, which is representing Fox Sports, said in a statement that Horowitz’s departure was “fully warranted,” and he called the accusations by Horowitz’s attorney “ill-informed and misguided.”

In the memo to employees, which was seen by Reuters, Eric Shanks, president of Fox Sports, wrote that everyone at Fox Sports “should act with respect and adhere to professional conduct at all times. These values are non-negotiable.”

Horowitz’s dismissal comes at a sensitive time for 21st Century Fox, which is controlled by media mogul Rupert Murdoch and is awaiting regulatory approval of its $15.2 billion acquisition of the UK’s Sky Plc.

Sexual harassment claims and lawsuits at another 21st Century Fox unit, Fox News, which led to the departures of former Chair Roger Ailes and star anchor Bill O’Reilly, have caused some investor concern about the future of the unit.

However, unlike at Fox News, there has been no litigation or settlements involving behavior at Fox Sports, according to a person familiar with the situation, who wished to remain anonymous because the matter is private.

In the memo, Shanks said he would take over Horowitz’s responsibilities until a replacement is named.

Horowitz had been in his position at Fox Sports since May 2015, according to his LinkedIn profile. A Fox web page on Horowitz had been taken down on Monday.

(Reporting by Jessica Toonkel; Editing by Leslie Adler)