Lexington County Sheriff James Metts entered that plea Tuesday in federal court in Columbia.
Metts was also allowed to post bond. He left court without speaking to reporters, and his next court appearance has not been scheduled.
Prosecutors say the longtime sheriff allowed friends to buy favors, accepting cash in return for agreeing to assist people who were in the country illegally and who were being detained.
A federal judge has ordered the sworn statements that led to Metts’ indictment be sealed. Court documents show agents have removed materials including computers, appointment books and written notes from the sheriff’s office.
Gov. Nikki Haley has suspended Metts from office, and Lewis McCarty is serving as acting sheriff.