No person shall be excused from testifying, or from producing any books, papers, contracts, agreements or documents at the trial or hearing of any person or company charged with violating any provisions of this chapter, on the ground that such testimony or evidence may tend to incriminate himself, but no person shall be prosecuted for any act concerning which he shall be compelled so as to testify or produce evidence, documentary or otherwise, except for perjury committed in so testifying.
Neb. Rev. Stat. §§ 44-396