On Tuesday, Tata alleged that Democratic board members Susan Evans and Christine Kushner may have violated the board's code of ethics.
He isn't convinced the pair has truly severed ties with the advocacy group Great Schools in Wake, which is a group fighting to stop Tata's new student assignment plan.
North Carolina NAACP President Rev. Dr. William Barber said he plans to pass along details to the accrediting agency "Advance Ed" as well as the Justice Department.
In the letter to Tata, Barber wrote, "Your decision to assail Ms. Evans and Ms. Kushner in a personal tone with ridiculous charges of 'unethical' behavior marks a low point in education leadership in Wake County. Not only is that charge entirely groundless. It also reveals a broad lack of self-awareness that heads toward hypocrisy."
Both Evans and Kushner have said they are no longer serving as activists for Great Schools in Wake.
"I'll just say that I'm free to associate with anyone I'd like, and I'll continue to do so," said Evans on Tuesday.
Both Evans and Tata said they hope to have a private meeting to work out the issues.
Kushner did not discuss the emails with reporters.