Mo. Rev. Stat. § 36.410

If any employee in a position subject to this law shall willfully refuse or fail to appear before any court or judge, any legislative committee, or any officer, board or body authorized to conduct any hearing or inquiry, or having appeared shall refuse to testify or answer any question relating to the affairs or government of the state or the conduct of any state officer or employee on the ground that his testimony or answers would tend to incriminate him, or shall refuse to waive immunity from prosecution on account of any matter about which he may be asked to testify at any such hearing or inquiry, he shall forfeit his position and shall not be eligible for appointment to any position under the provisions of this chapter.