The NFL and the Washington Commanders covered up decades of sexual misconduct, a US report has found.

Its 79-page report says team owner Dan Snyder “permitted and participated in the workplace misconduct”.

The NFL said it is “committed” to keeping the sport free of such issues.

“The NFL and the 32 clubs have implemented substantial and effective programs to advance this commitment at all of our facilities,” it said.

The report also said businessman Snyder, who has owned the Commanders – previously known as the Redskins – since 1999, also “engaged in tactics used to intimidate, surveil and pay off victims”.

“Sexual harassment, bullying and other toxic conduct pervaded the Commanders’ workplace, perpetuated by a culture of fear instilled by the team’s owner,” it says.

Representative Carolyn B Maloney, chair of the oversight and reform committee, said the congressional report “shows how one of the most powerful organisations in America, the NFL, mishandled pervasive sexual harassment and misconduct”.

“Our report tells the story of a team rife with sexual harassment and misconduct, a billionaire owner intent on deflecting blame and an influential organisation that chose to cover this up rather than seek accountability and stand up for employees,” she added.

The report includes a series of allegations against Snyder, including that he “inappropriately touched” a former employee.

Another ex-employee said team executives “tasked us with producing a video for Snyder of sexually suggestive footage of cheerleaders, obviously unbeknownst to any of the women involved”.

The report said sexual misconduct of other senior male employees was ignored and played down by the Commanders’ leadership, “perpetuating a toxic workplace culture”.

It also said Snyder interfered with the investigation by intimidating witnesses.

Allegations of widespread sexual harassment and abuse came to light in 2020 after a report in the Washington Post.

The Commanders were fined $10m (£7.3m) a year later after a review by the NFL, led by independent counsel Beth Wilkinson, investigated workplace culture at the franchise.

But the latest report says the NFL was aware of “Snyder’s serious interference with the Wilkinson investigation but failed to take adequate action to prevent it”.

“The NFL misled the public about its handling of the Wilkinson investigation and continues to minimise workplace misconduct across the league, highlighting the need for Congress to act,” it says.

“Despite the NFL’s knowledge, through its internal investigation, that the team’s owner permitted and participated in the workplace misconduct and engaged in tactics used to intimidate, surveil and pay off victims, the NFL aligned its legal interests with the Commanders, failed to curtail these abusive tactics and buried the investigation’s findings.”

The NFL denied that accusation, calling the Wilkinson report “independent and thorough”.

“No individual who wished to speak to the Wilkinson firm was prevented from doing so by non-disclosure agreements,” a statement said.

“And many of the more than 150 witnesses who participated in the Wilkinson investigation did so on the condition that their identities would be kept confidential.

“Far from impeding the investigation, the common interest agreement enabled the NFL efficiently to assume oversight of the matter and avoided the potential for substantial delay and inconvenience to witnesses.

“Following the completion of Ms. Wilkinson’s investigation, the NFL issued a public release and imposed a record-setting fine on the club and its ownership.

“The club also implemented a series of recommendations by the Wilkinson firm and an independent firm has monitored the implementation of those recommendations through regular reviews of the Commanders’ workplace.

“All of these reviews, which were shared with the Committee, have concluded that the Commanders have made significant improvements in workplace culture and policies.”