No person shall be excused from giving evidence upon any investigation or prosecution for any offense mentioned in this code or in any ordinance hereinafter enacted, upon the grounds that such testimony or evidence might tend to convict him or her of a crime. But such answer or evidence shall not be received against him or her upon any criminal proceeding or prosecution, except in a prosecution against him or her for perjury committed in giving such testimony.
(Prior Code, § 5-3-7)