Two days after Sophia Bush, Hilarie Burton and the female cast of One Tree Hill joined with the show's crew to write a letter accusing former showrunner Mark Schwahn of "traumatizing" sexual harassment, Schwahn has been suspended from his current show, E!'s The Royals

“E!, Universal Cable Productions and Lionsgate Television take sexual harassment allegations very seriously, investigate them thoroughly and independently, and take appropriate action," the companies said in a statement shared with USA TODAY on Wednesday. "Lionsgate has suspended Mark Schwahn from The Royals as we continue our investigation.”

The companies do not detail whether the allegations mention in the statement relate to production of The Royals. Season 4 of the royal soap, which stars Elizabeth Hurley, completed filming in September and will be broadcast in 2018.  

Bethany Joy Galeotti, Shantel Van Santen and Sophia Bush pose at The CW's presentation of 'An Evening with One Tree Hill' in 2011.

On Monday, the One Tree Hill stars penned a letter in support of former Tree Hill writer Audrey Wauchope, who detailed in a series of weekend tweets the treatment female crew endured on the show, which aired on WB from 2003 to 2006, and on the CW from 2006 to 2012.

Schwahn created the series and was the overseeing showrunner for its entire eight-season run.

"All of the female cast members of One Tree Hill have chosen this forum to stand together in support of Audrey Wauchope and one another," said the letter published in the entertainment trade publication Variety.

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The letter stated that Schwahn's alleged chronic behavior on the show was an "open secret."

"Many of us were, to varying degrees, manipulated psychologically and emotionally. More than one of us is still in treatment for post-traumatic stress. Many of us were put in uncomfortable positions and had to swiftly learn to fight back, sometimes physically, because it was made clear to us that the supervisors in the room were not the protectors they were supposed to be. Many of us were spoken to in ways that ran the spectrum from deeply upsetting, to traumatizing, to downright illegal. And a few of us were put in positions where we felt physically unsafe. More than one woman on our show had her career trajectory threatened."

Much of the alleged offending behavior was done in a way that was it was kept from the studio, according to the letter. 

"We also understood that no one was fully unaware," the letter continued. "The lack of action that has been routine, the turning of the other cheek, is intolerable. We collectively want to echo the calls of women everywhere that vehemently demand change, in all industries."

Sophia Bush as Brooke and Hilarie Burton as Peyton Sawyer in 'One Tree Hill.'

The cast and crew had kept silent until now to protect the show's legacy.

"We want Tree Hill to remain the place 'where everything’s better and everything’s safe' for our fans; some of whom have said that the show quite literally saved their lives. But the reality is, no space is safe when it has an underlying and infectious cancer. We have worked at taking our power back, making the conventions our own, and relishing in the good memories. But there is more work to be done."

The letter was signed by a total of 18 cast and crew including Bush, Burton, Bethany Joy Lenz, Danneel Harris, Michaela McManus, Kate Voegele, Daphne Zuniga, India DeBeaufort, Bevin Prince, Jana Kramer, Shantel Van Santen, Allison Munn and the "brave crew" which included Wauchope and Rachel Specter.

In her Nov. 11 tweets, Wauchope discussed getting a job with Specter, her writing partner, on Tree Hill. 

"To say we were excited was an understatement. To say we left that job demoralized and confused is also an understatement," Wauchope tweeted.

Without naming Schwahn in the tweets, she wrote about a toxic environment where women risked unwanted touching during meetings and men on staff "were shown naked photos of an actress he was having an affair with." 

"The staff sat on couches. Female writers would try to get the spot where the showrunner wouldn't sit as to not be touched. Often men would help out by sitting next to him, thus protecting the women, Wauchope tweeted.

Sometimes these attempts to separate Schwahn would fail, she says.

"He'd just squeeze his disgusting body in between us and put his arms around us, grinning. (He'd) pet hair. He massaged shoulders. I know he did more but not to me so they're not my stories to share," Wauchope tweeted.

When the studio lawyers came for a sexual harassment seminar, Schwahn failed to show up, Wauchope wrote.

"I'm furious and sad and everything else for the women who have sat on that couch next to that man," Wauchope added. "And I'm furious and sad and everything else that, years later, I don't feel safe to be able to do anything real about this and that it seems to be happening all over this town."

Male members of the cast added their support Tuesday. Bryan Greenberg tweeted praise for the women, saying "I hope that their courage to tell the truth, will help put an end to the pervasive culture of harassment in the work place. There’s no place for it."

Chad Michael Murray issued a similar statement to Entertainment Weekly, saying "A new frontier has arrived & it’s an honor to see all women stand up to the opposition that has caused so much pain. Equal rights & equal treatment isn’t an option, it is mandatory. Equality, safety and respect for all is the goal."

USA TODAY reached out to a representative for Schwahn for comment but did not get a reply.

Schwahn is currently showrunning for the E! show The Royals. 

In a statement carried by Variety, E!, Universal Cable Productions and Lionsgate Television — the firms behind The Royals — said: "We are monitoring the information carefully. E!, Universal Cable Productions and Lionsgate Television are committed to providing a safe working environment in which everyone is treated respectfully and professionally.”