18 U.S.C. § 6002 — Immunity generally

If a witness refuses, claiming the privilege against self-incrimination, to testify or provide other information in a proceeding before or connected with (1) a United States court or grand jury, (2) a United States agency^*, or (3) either House of Congress, a joint committee, or a committee or subcommittee of either House, and the presiding person communicates an order issued under this title to the witness, the witness may not refuse to obey that order on self-incrimination grounds. However, testimony or other information compelled by the order, and information directly or indirectly obtained from it, may not be used against the witness in a criminal case. The exception is a prosecution for perjury, giving a false statement, or otherwise failing to obey the order.