Nevada gambling regulators introduced a new online system for the public to send in confidential complaints and tips after receiving a number of reports about Steve Wynn in the days after The Wall Street Journal published an article detailing sexual-misconduct allegations against the casino mogul.

Becky Harris, chairwoman of the Nevada Gaming Control Board, said the goal of the system is to have “a more efficient, more effective way for the public to communicate with the board.” Ms. Harris, who became chairwoman on Jan. 22,...