34 C.F.R. § 300.511
(c) Impartial hearing officer.
(1) At a minimum, a hearing officer—
(i) Must not be—
(f) Exceptions to the timeline. The timeline described in paragraph (e) of this section does not apply to a parent if the parent was prevented from filing a due process complaint due to—
(2) The LEA's withholding of information from the parent that was required under this part to be provided to the parent.
(Approved by the Office of Management and Budget under control number 1820-0600)
(Authority: 20 U.S.C. 1415(f)(1)(A), 1415(f)(3)(A)-(D))