2 C.F.R. § 200.435
(3) Fraud means:
(b) Costs.
(1) Except as otherwise described herein, costs incurred in connection with any criminal, civil, or administrative proceeding (including the filing of a false certification) commenced by the Federal Government, a State, local government, or foreign government, or joined by the Federal Government (including a proceeding under the False Claims Act), against the recipient or subrecipient, (or commenced by third parties or a current or former employee of the recipient or subrecipient who submits a whistleblower complaint of reprisal in accordance with 10 U.S.C. 4701 or 41 U.S.C. 4712), are not allowable if the proceeding:
(ii) Results in any of the following dispositions:
(d) Allowability of costs for proceeding commenced by State, local, or foreign government. If a proceeding referred to in paragraph (b) of this section is commenced by a State, local or foreign government, then the costs incurred may be allowed if the authorized Federal official determines that the costs were incurred as a result of:
(e) Allowability of costs in general. Costs incurred in connection with proceedings described in paragraph (b), and not made unallowable by that paragraph, may be allowed to the extent that: