Fox News host Bill O'Reilly in New York in 2016. Dimitrios Kambouris/Getty Images for Hollywood Reporter

Fox News' parent company, 21st Century Fox, is going to open an investigation into allegations of sexual harassment made against Bill O'Reilly, attorney Lisa Bloom told CNN's "Reliable Sources" on Sunday.

The investigation comes after Bloom and her client, Wendy Walsh, called Fox's workplace misconduct hotline, and placed an official complaint against O'Reilly on Wednesday. A recording of the call was also uploaded to YouTube.

"Today, @DrWendyWalsh and I officially called in her sexual harassment complaint against O'Reilly to FoxNews hotline," Bloom tweeted on Wednesday. "Fox News and O'Reilly have said no one has complained about him on their complaint line. That is no longer true. We have the proof."

Walsh was a regular guest on The O'Reilly Factor and was reportedly offered a paid contributor position at the network. After she refused an invitation to go to O'Reilly's hotel suite in 2013, a New York Times investigation found, he did not follow through on securing her a job at Fox News.

Walsh is one of several women who have made claims of sexual harassment against O'Reilly. He and Fox News paid out $13 million in settlements to five women who had previously accused the host of harassment, according to the Times.

The women's allegations, which the Times found date back to 2002, included complaints of verbal abuse, lewd comments, unwanted advances, and phone calls "in which it sounded as if Mr. O'Reilly was masturbating, according to documents and interviews."

Attorneys of Fox News told Bloom they would investigate Walsh's complaint against O'Reilly after she placed a call to the hotline, Bloom told CNN's Brian Stelter.

"I'm told that they are taking it seriously, and they are going to do the investigation that's legally required of them," she said.

O'Reilly has denied that there is any merit to the allegations against him. He hired crisis communications expert Mark Fabiani, who released a statement to the Times on behalf of his client.

"Just like other prominent and controversial people, I'm vulnerable to lawsuits from individuals who want me to pay them to avoid negative publicity," the statement said. "In my more than 20 years at Fox News Channel, no one has ever filed a complaint about me with the Human Resources Department, even on the anonymous hotline.

"But most importantly, I'm a father who cares deeply for my children and who would do anything to avoid hurting them in any way. And so I have put to rest any controversies to spare my children," it continued.

The statement also suggested that O'Reilly is a target of harassment claims because of his prominence and the revenue he rakes in for the network helming the top-rated cable news show in the country. His lawyer said in a separate statement that they are now considering legal action to defend O'Reilly's reputation.

Despite his denials, O'Reilly and the network have taken a PR hit since the allegations emerged – 60 companies have now pulled their advertisements from O'Reilly's time slot.

Fox News has been engulfed by a flurry of negative headlines in recent days, with allegations also surfacing from contributor Julie Roginsky, who became the latest woman to file a sexual harassment lawsuit against former Fox News CEO and Chairman Roger Ailes. Ailes was ousted from the network last summer after multiple women accused him of sexual misconduct.