Legislative immunity does not extend to activities by legislators that are without lawful authority under Constitutional law, statutory law or rules of the Legislature, including, but not limited to, the following:
(1) Using an unconstitutional procedure to enact legislation;
(2) Conducting an illegal investigation or an unlawful search or seizure;
(3) Performing another otherwise valid legislative act without proper legislative authority;
(4) Filing a false or incomplete report, disclosure or claim regarding an otherwise valid legislative act; or
(5) Using legislative office for private gain in violation of the provisions of chapter six-b of this code that define and enforce governmental ethics.