Supporters of the former national president, Warren David, say he was fired in November for questioning the group's handling of allegations that Imer Hamad sexually harassed women who worked in the Michigan office, the Detroit Free Press reported.
On Tuesday, the ADC'S Michigan branch said its annual gala, scheduled for Friday, had been canceled. The gala is one of the major events in the calendar for the large Arab-American community in the Detroit area.
The announcement came after protesters said they would picket the gala.
David, 61, who had been national president since 2011, left in November.
Hamad, who retired a few days earlier, has denied the sexual harassment allegations.
Raed Jarrer, the former national communications director, who, like David, questioned the ADC's policy on sexual harassment, was also dismissed.
Khaled Bey, who is originally from Detroit and now teaches law at UCLA, is involved in trying to change the organization.
"Warren David was fired for taking a principled stance," he said.