In any contested administrative hearing under this part, no person shall be excused from attending and testifying, or from producing books, papers, and records before the administrative law judge, or from obedience to the subpoena of the administrative law judge, on the ground or for the reason that the testimony or evidence, documentary or otherwise, required by him or her may tend to incriminate him or her or subject him or her to a penalty or forfeiture, provided that nothing contained in this Code section shall be construed as requiring any person to produce any books, papers, or records, or to testify in response to any inquiry, not pertinent to a question lawfully before the administrative law judge for determination. No evidence given by or required of any natural person shall be used or admitted against such a person in any criminal prosecution for any transaction, matter, or thing concerning which he or she may be required to testify or produce evidence, documentary or otherwise, before the administrative law judge in obedience to its subpoena; provided, however, that no person testifying shall be exempt from prosecution and punishment for perjury committed in so testifying.