38 U.S.C. § 5712: Validity of affidavits

Any such oath, affirmation, affidavit, or examination, when certified under the hand of any such employee by whom it was administered or taken and authenticated by the seal of the Department, may be offered or used in any court of the United States and without further proof of the identity or authority of such employee shall have like force and effect as if administered or taken before a clerk of such court.