N.H. Rev. Stat. § 282-A:124
In the discharge of the duties imposed by this chapter, the commissioner of the department of employment security, the chairman of an appeal tribunal, and any duly authorized representative of either of them shall have power to administer oaths and affirmations, take depositions, certify to official acts, and issue subpoenas to compel the attendance of witnesses and the production of books, papers, correspondence, memoranda, and other records deemed necessary as evidence in connection with a disputed claim or the administration of this chapter.
RSA 282-A:124
1917, 198:5. PL 175 :5. 1935, 146:1. 1937, 178:1. 1939, 138:19-21. 1941, 103:32. RL 211:5; 218:9. 1945, 138:20. 1947, 59:19-21. 1949, 185:13. 1950, 5, pt. 18:4-11; 9:1. 1951, 105:1. 1953, 209:7; 265:1. RSA 282:9(N). 1955, 77:2; 141:15, 21. 1957, 118:9-13. 1961, 88:30-35. 1963, 194:9. 1965, 208:10-13. 1967, 400:7, 10. 1969, 460:18, 19. 1973, 528:173, 174; 589:8. 1975, 393:3. 1981, 408:3, eff. Oct. 1, 1981.