N.C. Gen. Stat. § 15A-256
An officer executing a warrant directing a search of premises not generally open to the public or of a vehicle other than a common carrier may detain any person present for such time as is reasonably necessary to execute the warrant. If the search of such premises or vehicle and of any persons designated as objects of the search in the warrant fails to produce the items named in the warrant, the officer may then search any person present at the time of the officer's entry to the extent reasonably necessary to find property particularly described in the warrant which may be concealed upon the person, but no property of a different type from that particularly described in the warrant may be seized or may be the basis for prosecution of any person so searched. For the purpose of this section, all controlled substances are the same type of property.
N.C. Gen. Stat. § 15A-256