18 U.S.C. § 2517 : US Code - Section 2517: Authorization for disclosure and use of intercepted wire, oral, or electronic communications

      (1) Any investigative or law enforcement officer who, by any
    means authorized by this chapter, has obtained knowledge of the
    contents of any wire, oral, or electronic communication, or
    evidence derived therefrom, may disclose such contents to another
    investigative or law enforcement officer to the extent that such
    disclosure is appropriate to the proper performance of the official
    duties of the officer making or receiving the disclosure.
      (2) Any investigative or law enforcement officer who, by any
    means authorized by this chapter, has obtained knowledge of the
    contents of any wire, oral, or electronic communication or evidence
    derived therefrom may use such contents to the extent such use is
    appropriate to the proper performance of his official duties.
      (3) Any person who has received, by any means authorized by this
    chapter, any information concerning a wire, oral, or electronic
    communication, or evidence derived therefrom intercepted in
    accordance with the provisions of this chapter may disclose the
    contents of that communication or such derivative evidence while
    giving testimony under oath or affirmation in any proceeding held
    under the authority of the United States or of any State or
    political subdivision thereof.
      (4) No otherwise privileged wire, oral, or electronic
    communication intercepted in accordance with, or in violation of,
    the provisions of this chapter shall lose its privileged character.
      (5) When an investigative or law enforcement officer, while
    engaged in intercepting wire, oral, or electronic communications in
    the manner authorized herein, intercepts wire, oral, or electronic
    communications relating to offenses other than those specified in
    the order of authorization or approval, the contents thereof, and
    evidence derived therefrom, may be disclosed or used as provided in
    subsections (1) and (2) of this section. Such contents and any
    evidence derived therefrom may be used under subsection (3) of this
    section when authorized or approved by a judge of competent
    jurisdiction where such judge finds on subsequent application that
    the contents were otherwise intercepted in accordance with the
    provisions of this chapter. Such application shall be made as soon
    as practicable.
      (6) Any investigative or law enforcement officer, or attorney for
    the Government, who by any means authorized by this chapter, has
    obtained knowledge of the contents of any wire, oral, or electronic
    communication, or evidence derived therefrom, may disclose such
    contents to any other Federal law enforcement, intelligence,
    protective, immigration, national defense, or national security
    official to the extent that such contents include foreign
    intelligence or counterintelligence (as defined in section 3 of the
    National Security Act of 1947 (50 U.S.C. 401a)), or foreign
    intelligence information (as defined in subsection (19) of section
    2510 of this title), to assist the official who is to receive that
    information in the performance of his official duties. Any Federal
    official who receives information pursuant to this provision may
    use that information only as necessary in the conduct of that
    person's official duties subject to any limitations on the
    unauthorized disclosure of such information.
      (7) Any investigative or law enforcement officer, or other
    Federal official in carrying out official duties as such Federal
    official, who by any means authorized by this chapter, has obtained
    knowledge of the contents of any wire, oral, or electronic
    communication, or evidence derived therefrom, may disclose such
    contents or derivative evidence to a foreign investigative or law
    enforcement officer to the extent that such disclosure is
    appropriate to the proper performance of the official duties of the
    officer making or receiving the disclosure, and foreign
    investigative or law enforcement officers may use or disclose such
    contents or derivative evidence to the extent such use or
    disclosure is appropriate to the proper performance of their
    official duties.
      (8) Any investigative or law enforcement officer, or other
    Federal official in carrying out official duties as such Federal
    official, who by any means authorized by this chapter, has obtained
    knowledge of the contents of any wire, oral, or electronic
    communication, or evidence derived therefrom, may disclose such
    contents or derivative evidence to any appropriate Federal, State,
    local, or foreign government official to the extent that such
    contents or derivative evidence reveals a threat of actual or
    potential attack or other grave hostile acts of a foreign power or
    an agent of a foreign power, domestic or international sabotage,
    domestic or international terrorism, or clandestine intelligence
    gathering activities by an intelligence service or network of a
    foreign power or by an agent of a foreign power, within the United
    States or elsewhere, for the purpose of preventing or responding to
    such a threat. Any official who receives information pursuant to
    this provision may use that information only as necessary in the
    conduct of that person's official duties subject to any limitations
    on the unauthorized disclosure of such information, and any State,
    local, or foreign official who receives information pursuant to
    this provision may use that information only consistent with such
    guidelines as the Attorney General and Director of Central
    Intelligence shall jointly issue.