After a five-month internal investigation, NBCUniversal said on Wednesday that it found no evidence the leaders of its news division were aware of allegations of sexual misconduct made by four women against fired “Today” show anchor Matt Lauer.

"We found no evidence indicating that any NBC News or 'Today' show leadership, News HR or others in positions of authority in the News Division received any complaints about Lauer’s workplace behavior prior to Nov. 27, 2017," the report states.

The investigation, led by NBCUniversal general counsel Kim Harris, in consultation with two outside law firms, also found that NBC News did not have a broader problem with sexual harassment in its workplace.

“The investigation team does not believe that there is a widespread or systemic pattern of behavior that violates company policy or a culture of harassment in the News Division," the report states.

But the report found that several people at NBC News were aware that Lauer "would openly engage in sexually oriented banter in the workplace," and included interviews with several women who described what they considered to be sexual overtures from Lauer.

The women interviewed said they did not report this behavior to people in authority.

The report found that many employees are reluctant to report conduct issues to the news division's human resources department, in part because they are not familiar with the department, feared retaliation and believed the reports would not be kept confidential.

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In response, Andrew Lack, the chairman of NBC News, issued a separate memo announcing new methods of reporting workplace misconduct, including a way to voice complaints to an outside law firm. Managers would undergo a "training surge," he said, to help create a respectful workplace environment.

Rick Rossein, a law professor specializing in employment discrimination at the School of Law at the City University of New York, said that underreporting of sexual harassment in all workplaces is a serious issue that needs to be addressed.

"Between 34 percent and 40 percent of women in the workplace are being sexually harassed, and 75 percent of those never make a peep. They don't come forward,” Rossein said. “On the other hand, it's past the day where management can say, ‘we didn't receive a complaint.’"

Rossein said women need to feel empowered to come forward if they are harassed or hear about improper behavior.

"One thing I'm saying is anytime you hear something, it has to be mandatory reporting for all managers, even if they hear a rumor,” Rossein said.

NBC News management has said it had not received complaints about Lauer prior to Nov. 27 but fired him after a woman and her lawyer stepped forward with allegations of serious sexual impropriety. The investigation found that none of the four women “had told their direct manager or anyone else in a position of authority about their sexual encounters with Lauer.” But the report said the investigation found their allegations to be credible.

Lauer called some of the accusations “untrue or mischaracterized” in a statement after his firing. But he said that “there is enough truth in these stories to make me feel embarrassed and ashamed.”

The report also addressed news reports that Lauer had a button on his desk that locked his office door. In fact, the report said, the button closed the door but did not lock it. The device is common in NBC executive offices, the report said.

The investigation team interviewed 68 individuals and included former NBC News leaders and former human resource leaders, according to the document issued Wednesday morning.

The seven-page report said that investigations into other concerns raised through the process are ongoing.

Public interest in the workplace culture of NBC News began in November after Lauer’s firing and was recently revisited when two women accused former NBC News anchor Tom Brokaw of unwanted sexual advances. Tom Brokaw has denied the allegations.

NBC News had been criticized for not hiring an outside law firm to investigate the Lauer situation, but the report noted the company had worked with two law firms, Davis Polk and Proskauer Rose. The firms reviewed the methodology, findings and conclusions of the investigation, according to an NBCUniversal spokesperson.

Ari Wilkenfeld, an attorney for one of the women who accused Matt Lauer of sexual misconduct, said in a statement that NBC should have another investigation conducted by an outside firm.

“The report tells us something important – that a number of employees feel they cannot come forward with harassment allegations,” said Wilkenfield, who also represented Linda Vester, who said Brokaw had made unwanted sexual advances toward her. “It also makes an important point of why we need an independent investigation – so that there won’t be any seeds of doubt about what really happened.”

Other news organizations have been grappling with similar issues, including CBS News, PBS and NPR. CBS News has been subject to allegations that it failed to curtail the behavior of Charlie Rose, an anchor of "This Morning," who was also host of a show for PBS. The Washington Post reported that three managers at CBS were warned about Rose.