BOSTON — The Massachusetts Gaming Commission, stunned by allegations that the casino mogul Stephen Wynn had engaged in decades of sexual misconduct, vowed Wednesday to conduct an investigation into Mr. Wynn, who is in the midst of building a $2.4 billion luxury casino resort outside Boston.

The gaming commission has broad authority to exercise a range of options, including levying a fine or even revoking Mr. Wynn’s license to operate the casino.

The project, called Wynn Boston Harbor, is the largest single-phase development in state history and is scheduled to open next year. Thousands of jobs are associated with the project, which is a crucial part of the fledgling casino industry in Massachusetts.

The Wall Street Journal reported last week that Mr. Wynn, one of the most powerful figures in the casino industry, had engaged in serious sexual misconduct, including exposing himself, pressuring employees for sex and paying $7.5 million to a former manicurist who said that Mr. Wynn had forced her to have sex with him. Mr. Wynn has denied the allegations.