President of The Humane Society of the United States under investigation for workplace misconduct

— -- The president and chief executive officer of the Humane Society of the United States is under investigation for alleged workplace misconduct, the nonprofit charity confirmed ahead of a published report on Tuesday claiming three women filed sexual harassment complaints against him.

Wayne Pacelle, who has headed the nation's largest animal care provider since 2004, is the subject of an internal investigation being handled by a law firm the Humane Society hired.

"The Board of Directors of the Humane Society of the United States retained [the law firm] Morgan Lewis in December to conduct an investigation of allegations of workplace misconduct against our CEO, Wayne Pacelle. A special committee of the board is overseeing the investigation and reviewing its findings," Eric Bernthal, chairman of the agency's board of directors, said in a statement.

"We do not have information that can be shared regarding the investigation, its findings, or board actions at this time," Bernthal added. "We believe it is important to deal in substance and not rumors, and our process is designed to ensure confidentiality and fair consideration of these issues."

Anna West, a spokeswoman for the Humane Society, told ABC News that the 52-year-old married Pacelle was not available Tuesday for comment.

The Humane Society of the United States, headquartered in Washington, D.C., released Bernthal's statement in advance of a Washington Post article Tuesday reporting that three women who worked for the Humane Society filed sexual harassment complaints against him for behavior dating back to 2005.

Citing a Humane Society memo, the newspaper reported that settlements were offered to three other women who worked for the organization and claimed they were demoted or fired after reporting Pacelle's behavior.

In an interview with the Washington Post, Pacelle denied the new allegations of sexual harassment, saying, "This is a coordinated attempt to attack me and the organization. And I absolutely deny any suggestion that I did anything untoward."