The Massachusetts Gaming Commission released the report at the start of a three-day hearing focussed on whether Wynn Resorts remains suitable to retain a licence needed to run a $2.6 billion (1.99 billion pounds) casino just outside Boston it plans to open in June.

Wynn has called the sexual misconduct accusations "preposterous." His lawyer had no immediate comment on Tuesday.

The report by the commission's investigations and enforcement bureau followed a January 2018 article by The Wall Street Journal detailing allegations that the billionaire had engaged in a decades-long pattern of sexual misconduct.

His subsequent exit as the company's chief executive and sale of his 11.8-percent stake in the company made him one of the most prominent corporate executives to lose his job amid the #MeToo movement, which has highlighted longstanding patterns of sexual harassment and abuse in major U.S. institutions.

Wynn Resorts said in a Tuesday statement it arranged for Wynn to leave without severance, cooperated with the Massachusetts inquiry and has parted ways with any employee who did not investigate or report allegations against Wynn.

Wynn Resorts shares were up 1.9 percent at $131.85.

Massachusetts investigators concluded that over several years, a limited group of executives and employees disregarded company policies when it came to allegations of sexual misconduct against Wynn involving other employees.

The 199-page report said certain executives, with the help of outside lawyers, also took steps after learning about allegations against Wynn to conceal them.

"Their efforts at secrecy made it exceedingly difficult, if not impossible, for gaming regulators to detect this potentially derogatory information through typical regulatory means," the report said.

The report said the actions of those now-former executives "appear to have contributed to a culture where employees were reluctant to report allegations against Mr. Wynn to management."

The Las Vegas-based company received its Massachusetts licence in 2013, allowing it to move forward with building the 671-room "Encore Boston Harbor" in Everett, Massachusetts.

The five-member commission is not expected to issue a decision for several weeks. It can impose conditions on the Las Vegas-based company's licence or revoke it entirely.

Nevada casino regulators, following a similar investigation into its response to allegations against Wynn, in February fined the company $20 million.

(Reporting by Nate Raymond; Editing by Meredith Mazzilli and Nick Zieminski)

By Nate Raymond