TEWKSBURY, Mass. —

A longtime Market Basket board member was removed earlier this month, shortly before an attorney representing the remaining members accused him of cooperating with the public relations team representing the grocery chain's suspended CEO.

Arthur T. Demoulas was placed on leave in May, when the board accused him of planning a retaliatory work stoppage and hired a law firm to investigate. The two sides are scheduled to meet with a mediator on Sept. 3, but the feud has continued to leak into public view.

Last week, attorney Harvey Wolkoff wrote a warning letter to Demoulas in which the board accused Demoulas of orchestrating a series of recent public relations attacks on the company ahead of a scheduled mediation session next month.

Wolkoff's letter alleged that De

See Full Page