N.H. Rev. Stat. Ann. § 147:3

Health officers of towns, and each of them, shall inquire into all nuisances and other causes of danger to the public health, and for the purpose of such investigations, or whenever they shall know or have cause to suspect that any nuisance or other thing injurious to the public health is in any building, vessel, or enclosure they may obtain an administrative inspection warrant under RSA 595-B, including authority to forcibly enter therein and make such search, pursuant to RSA 595-B:5.