and made after adequate opportunity to present objections . . . Id., at 195 (footnotes omitted).
We cited Oklahoma Press with approval in See v. City of Seattle, supra, a companion case to Camara, and described the constitutional requirements for administrative subpoenas as follows:
“It is now settled that, when an administrative agency subpoenas corporate books or records, the Fourth Amendment requires that the subpoena be sufficiently limited in scope, relevant in purpose, and specific in directive so that compliance will not be unreasonably burdensome.” See v. City of Seattle, supra, at 544 (footnote omitted).
See also United States v. Morton Salt Co., 338 U. S. 632, 652-653 (1950).
Thus although our cases make it clear that the Secretary of Labor may issue an administrative subpoena without a warrant, they nonetheless provide protection for a subpoenaed employer by allowing him to question the reasonableness of the subpoena, before suffering any penalties for refusing to comply with it, by raising objections in an action in district court. See v. City of Seattle, supra, at 544-545; Oklahoma Press, supra, at 208-209. Our holding here, which simply reaffirms our holding in Oklahoma Press, in no way leaves an employer defenseless against an unreasonably burdensome administrative subpoena requiring the production of documents. We hold only that the defenses available to an employer do not include the right to insist upon a judicial warrant as a condition precedent to a valid administrative subpoena.
Appellee insists that “[t]he official inspection procedure used by the appellants reveal[s] that the use of the administrative subpoena is inextricably intertwined with the entry process,” Brief for Appellee 11, and states that it is appel