28 U.S. Code § 1826 - Recalcitrant witnesses
(a) Whenever a witness in any proceeding before or ancillary to any court or grand jury of the United States refuses without just cause shown to comply with an order of the court to testify or provide other information, including any book, paper, document, record, recording or other material, the court, upon such refusal, or when such refusal is duly brought to its attention, may summarily order his confinement at a suitable place until such time as the witness is willing to give such testimony or provide such information. No period of such confinement shall exceed the life of—
before which such refusal to comply with the court order occurred, but in no event shall such confinement exceed eighteen months.
(b) No person confined pursuant to subsection (a) of this section shall be admitted to bail pending the determination of an appeal taken by him from the order for his confinement if it appears that the appeal is frivolous or taken for delay. Any appeal from an order of confinement under this section shall be disposed of as soon as practicable, but not later than thirty days from the filing of such appeal.
(c) Whoever escapes or attempts to escape from the custody of any facility or from any place in which or to which he is confined pursuant to this section or section 4243 of title 18, or whoever rescues or attempts to rescue or instigates, aids, or assists the escape or attempt to escape of such a person, shall be subject to imprisonment for not more than three years, or a fine of not more than $10,000, or both.