The Massachusetts Gaming Commission has been regularly violating the state’s Open Meeting Law by conducting public business during weekly closed-door “commissioners’ lunches” and other private get-togethers, according to an attorney general’s investigation prompted by a Herald special report.

“Discussion of matters related to the operation of the Commission appears to have become a regular part of the lunches,” Attorney General Maura Healey’s office wrote in a letter to Gaming Commission Chairman Stephen Crosby yesterday.

The Herald first reported in July that the panel had held more than 100 hours of secret meetings, including weekly clandestine “commissioners’ lunches” in their downtown office. The commission asked the attorney general to investigate the private meetings.

The AG’s office found the “lunches” quickly became forums for private discussions that should have been aired in the open, with topics including:

Staff morale in light of pending litigation and news coverage of the panel;

The need for a contingency plan if the November 2014 ballot referendum — a casino repeal initiative — were to pass;

Commissioner James McHugh’s resignation, which was announced at one of the lunches;

Commissioner Bruce Stebbins’ reappointment, including his “strengths,” and a contingency plan in case he wasn’t;

An “after-action report” on the Eastern Massachusetts casino license process that was ultimately awarded to Wynn Resorts; the AG also found that Commissioner Enrique Zuniga said at one of the lunches that the process had too many regulations;

Crosby’s and McHugh’s reports on discussions with the AG’s office over open litigation against the commission — which should have been publicly posted;

A decision whether to retain a management consultant;

Ongoing construction at Plainridge Park; and

Adding members with anti-casino gaming interests to the Gaming Policy Advisory Committee.

Outside of the lunches, the commission held a series of other private meetings, including:

After Crosby recused himself from the Eastern Massachusetts casino licensing process, the four remaining commissioners met privately to “discuss the need to research strategies for avoiding deadlock” in awarding the license. “Because the May 20, 2014 conversation concerned Commission business — namely, how decisions would be made — it should have taken place during a meeting,” Healey’s office wrote. “This private discussion therefore violated the Open Meeting Law.”

Regular 15-minute “stand-up” meetings where they talked about individual projects they were working on — another violation of the law, the AG found.

A conference call took place on Sept. 17, 2014, about creating a “closing plan” for Suffolk Downs after losing to Wynn for the gaming license, though none of the commissioners recalled being part of the discussion.

The AG ruled that some “personal gatherings” did not violate the open meeting law, including a Nov. 3, 2014, meeting at Crosby’s home about “interpersonal dynamics between the Commissioners” and a Dec. 10, 2014, meeting to plan a holiday party and discuss “the preferred rules for a Yankee swap.”

Although not a violation, Healey’s investigation also revealed that casino mogul Steve Wynn visited the commissioners individually on Sept. 19, 2014, just days after they awarded Wynn a casino license. Wynn brought “samples of bed linens to show the Commissioners their high quality,” the report stated.

The AG’s office advised “caution” on future commissioners’ lunches and urged them to receive Open Meeting Law training.

“The Commission is now closely reviewing this information and looks forward to scheduling the recommended training session offered by the AG’s Office,” said Commission spokeswoman Elaine Driscoll.