27 C.F.R. § 70.22
(b) Summonses. For the purposes described in paragraph (a) of this section the appropriate TTB officers are authorized to summon the person liable for tax or required to perform the act, or any officer or employee of such person, or any person having possession, custody, or care of books of accounts containing entries relating to the business of the person liable for tax or required to perform the act, or any person deemed proper, to appear before a designated officer or employee of the Bureau at a time and place named in the summons and to produce such books, papers, records, or other data, and to give such testimony, under oath, as may be relevant or material to such inquiry; and take such testimony of the person concerned, under oath, as may be relevant or material to such inquiry. Such TTB officer may designate an appropriate TTB officer as the individual before whom a person summoned pursuant to 26 U.S.C. 7602 shall appear. Any such officer, when so designated in a summons, is authorized to take testimony under oath of the person summoned and to receive and examine books, papers, records, or other data produced in compliance with the summons. The authority to issue a summons may not be redelegated. See § 70.302 of this part for rules concerning payments to certain persons who are summoned to give information to the Bureau under 26 U.S.C. 7602 and this section.
(Aug. 16, 1954, Chapter 736, 68A Stat. 901; (26 U.S.C. 7602))
[T.D. ATF-6, 38 FR 32445, Nov. 26, 1973, as amended by T.D. ATF-42, 42 FR 8367, Feb. 10, 1977; T.D. ATF-301, 55 FR 47608, Nov. 14, 1990; T.D. ATF-331, 57 FR 40328, Sept. 3, 1992; T.D. ATF-450, 66 FR 29023, May 29, 2001; T.D. TTB-91, 76 FR 5481, Feb. 1, 2011]