N.H. Rev. Stat. Ann. § 516:7

Every court, justice, and notary, before whom a person has been summoned to appear and testify or to give a deposition, may bring the person neglecting or refusing to appear or to testify or to give a deposition, by attachment, before them, and if, on examination, such person has no reasonable excuse, such person shall be guilty of a violation, and may be ordered to pay costs.