"We have concluded our investigation and Mark will not be returning to The Royals," Lionsgate Television, which produces the show, told The Hollywood Reporter. "The fourth season of the show has already completed production and will air as scheduled on E! in the spring."
Schwahn last worked on the fourth season of the show, which finished production in September and is slated to air in 2018. Lionsgate and E! haven't said if they plan on renewing the show to continue it under a different showrunner.
Back on Nov. 11, One Tree Hill writer Audrey Wauchope accused Schwahn of judging female writers based on their looks. Wauchope said she and her writing partner, Rachel Specter, both left the show feeling "demoralized and confused."
Wauchope listed several examples of sexual misconduct, including showing nude photos of an actress he claimed he be having an affair with to male writers and asking Specter if she still wanted to go through with her wedding while blocking her from leaving his office.
Since Wauchope's tweets, Schwahn was suspended by Lionsgate and E! on Nov. 15. One Tree Hill actress Hilarie Burton accused Schwahn of sexual misconduct as well, and The Royals actress Alexandra Park tweeted that she felt "exposed to this reprehensible behavior."
Elizabeth Hurley, the star of The Royals, said the allegations against Schwahn were a "shocking surprise" to her and vowed to help anyone she sees being "treated unfairly" in the future.
"I may have failed Alexandra, but it won't happen again on my watch," Hurley wrote on Twitter.
The Royals centers on a fictional modern version of the British Royal Family, with Hurley as the Queen. William Moseley, Park, Jake Maskall, Tom Austen, Genevieve Gaunt and Max Brown also star.