Tony Robbins is known for using coarse language and unorthodox methods at his life-coaching seminars. He has had session participants, including Oprah Winfrey, walk on hot coals. He has persuaded Salesforce CEO Marc Benioff to jump off a bridge into a snake-infested river.

Robbins says his unconventional methods have helped millions of people overcome personal problems and reach their full potential. But allegations uncovered in a new investigation by BuzzFeed News paint a picture of a dark side to his approach. The report details allegations of inappropriate behavior, including sexual harassment, by five women who worked for Robbins's company, Robbins Research International, in the 1990s and early 2000s.

Robbins's lawyers denied the allegations in a letter to BuzzFeed News, saying Robbins never engaged in any misconduct and went to "great lengths to ensure the safety, comfort and enjoyment of all attendees."

Robbins called the report "an inaccurate, agenda-driven version of the past, pierced with falsehoods" in a Medium post, published Friday. A Robbins spokeswoman referred Inc. to the Medium post when asked for comment.

The report also includes statements from Robbins's former director of security and other former RRI employees, expressing concern over what they considered dangerous conditions at Robbins's events, as well as Robbins's harsh treatment of abuse victims.

Robbins came under fire last year when a video surfaced of him criticizing the #MeToo movement. (He apologized.) Recently many other entrepreneurs and business leaders also have been accused of misconduct. The claims against Robbins serve as yet another reminder that many prominent influencers' past conduct may fall short when it comes to today's appropriate workplace standards.