34 C.F.R. § 33.14
(a) The investigating official, the reviewing official, and any employee or agent of the Department who takes part in investigating, preparing, or presenting a particular case may not, in that case or a factually related case:
(c) Except as provided in paragraph (a) of this section, the representative for the Government may be employed anywhere in the Department, including in the offices of either the investigating official or the reviewing official.
(Authority: 31 U.S.C. 3809(l)(2))