"Now is the best time in the world to be a woman and I have a platform so it's time to use my voice," The Rookie actress wrote on Instagram Saturday
Credit: Tony Rivetti/ABC

Afton Williamson, the female lead of ABC crime dramedy The Rookie, says she has quit the series after her complaints of racial bullying and sexual harassment on the first season set went ignored by higher-ups.

On Sunday, Williamson, who played training officer Talia Bishop opposite Nathan Fillion’s title character on the series, confirmed reports that she would not be returning for the show’s upcoming sophomore season — sharing a post on Instagram that detailed her reason for the exit.

In the post, the 34-year-old actress claimed that from the filming of the pilot in Spring 2018, throughout all of the first season, she “experienced racial discrimination/racially charged inappropriate comments from the hair department and bullying from executive producers,” as well as sexual harassment from an unnamed guest star.

She alleged that the bullying from the hair department escalated at the season 1 wrap party when the department’s head sexually assaulted her.

PEOPLE has not been able to independently verify Williamson’s claims.

A rep for ABC Studios told PEOPLE in a statement that Williamson’s claims were being investigated by Entertainment One, The Rookie‘s production company.

“In late June, eOne made us aware and informed us that they launched an investigation that is ongoing,” the ABC spokesperson said. “The safety of working environments is a top priority for us, and we take this matter very seriously.”

Entertainment One also released a statement to PEOPLE which read, “We take claims of this nature very seriously. We have initiated an independent investigation which is ongoing and as such, it would not be appropriate to comment at this time.”

On Monday, ABC’s network entertainment president, Karen Burke, addressed Williamson’s claims while at ABC’s TCA session.

“I am frustrated, I don’t have a lot of answers; I wish I had more,” Burke said. “I heard at the end of June that there were allegations, and an investigation has been launched. We are waiting for answers. As soon as we learn more, we will make determination based on what’s found.”

She went on to say that she hopes eOne’s investigation into the matter would provide “results that are independent and trustworthy” in a way that “will guide us how to handle similar situations in the future.”

Williamson wrote in her Instagram post that she originally took her on-set complaints to The Rookie’s creator, showrunner, and executive producer, Alexi Hawley, who she claimed did nothing to look into the issues.

“The sexual harassment though reported directly to [Hawley] remained undocumented and was not reported to HR as promised,” she wrote. “HR protocol was never adhered to … and an investigation was never issued for any of my claims.”

Reps for Alexi Hawley did not immediately respond to PEOPLE’s request for comment.

Williamson claimed that she eventually called a meeting following the show’s season 2 pickup in June.

“This meeting included the showrunner and two other producers as well as my agent and SAG-AFTRA Union Rep,” Williamson said. “It was clear to all present in the meeting that the showrunner had not shared my reports with any of the producers.”

Though Williams says the head of the hair department was fired after the alleged sexual assault at the wrap party, the actress noted that the department head was not fired until after “an entire year of outward racism/racially charged language and bullying behavior in and out of the hair and makeup trailer.”

As for the unnamed guest star, Williamson said she was “assured that the actor would be fired” after her initial claim of sexual harassment, but was “asked to film with him the very next day as a courtesy to the script, even though we had not begun filming the episode yet.”

“This actor reappeared on our call sheet at the end of the season, I was even written in scenes with him,” she said. “I asked the showrunner about this and he admitted to me that the actor had not been fired nor had he gotten HR involved.”

Afton Williamson
Afton Williamson
| Credit: Image Group LA via Getty

In the end, Williamson says she decided to leave the show on her own terms.

“I was asked to return this season, and promised that ‘everything was handled.’ The investigation hadn’t even begun and season 2 had already started filming,” the actress claimed. “I turned it down and I walked.”

“Now is the best time in the world to be a woman and I have a platform so it’s time to use my voice,” Williamson added. “Strength comes from within. It comes from above. ‘Greater is He that is within me than he that is in the world’ ❤️🙏🏽.”

Season 2 of The Rookie is set to premiere on ABC on Sept. 29.