(1) The department shall cause to be investigated any complaint which is filed under this part if the complaint is in writing, signed by the complainant, and is legally sufficient. A complaint is legally sufficient if it contains ultimate facts which show that a violation of this part, or the rules adopted under this part, may have occurred. In order to determine legal sufficiency, the department may require supporting information or documentation. The department may investigate an anonymous complaint or a complaint made by a confidential informant if the complaint is in writing and is legally sufficient, if the alleged violation of law or rules is substantial, and if the department has reason to believe, after preliminary inquiry, that the alleged violations in the complaint are true. The department may initiate an investigation if it has reasonable cause to believe that a person has violated this part or the rules adopted under this part.
(2) A privilege against civil liability is hereby granted to any complainant or any witness with regard to information furnished with respect to any investigation or proceeding pursuant to this part, unless the complainant or witness acted in bad faith or with malice in providing such information.
(3) Whoever knowingly makes a false complaint in writing under this part commits a misdemeanor of the second degree, punishable as provided in s. 775.082, s. 775.083, or s. 837.06. 
