18 U.S.C. § 3504: Litigation concerning sources of evidence

upon a claim by a party aggrieved that evidence is inadmissible because it is the primary product of an unlawful act or because it was obtained by the exploitation of an unlawful act, the opponent of the claim shall affirm or deny the occurrence of the alleged unlawful act; disclosure of information for a determination if evidence is inadmissible because it is the primary product of an unlawful act occurring prior to June 19, 1968 , or because it was obtained by the exploitation of an unlawful act occurring prior to June 19, 1968 , shall not be required unless such information may be relevant to a pending claim of such inadmissibility; and no claim shall be considered that evidence of an event is inadmissible on the ground that such evidence was obtained by the exploitation of an unlawful act occurring prior to June 19, 1968 , if such event occurred more than five years after such allegedly unlawful act. As used in this section “unlawful act” means any act the use of any electronic, mechanical, or other device (as defined in section 2510(5) of this title ) in violation of the Constitution or laws of the United States or any regulation or standard promulgated pursuant thereto.