Testimony or documentary evidence of any kind obtained by the board during the investigation of a complaint is not subject to discovery or disclosure under chapter 15-6 or under any other provision of law and is not admissible as evidence in any legal proceeding, unless the complaint becomes a contested case under chapter 1-26 . No person who has participated in the investigation of a complaint on behalf of the board may testify as an expert witness or be compelled to testify for any party in any civil action, if the subject matter of the complaint investigated is a basis for the civil action.
SDCL 36-33-60