The Dothan Personnel Board announced some members have been receiving anonymous letters. The board met Wednesday to interrogate other officers as part of the investigation.
The personnel board investigation began after a series of anonymous letters criticizing police Chief John White were circulated late last year.
Captain Jim Smith was accused of writing those letters and he eventually resigned.
The board's investigation was originally launched to determine if Smith had been forced to quit.
Board Chairman Gary Griffin said some members have received anonymous letters and phone calls recently. Griffin says some of the anonymous communications claim city employees have been divulging unauthorized information about the case.