Honolulu ? The head of a labor recruiting company accused of exploiting 400 workers from Thailand and forcing them to work on U.S. farms pleaded not guilty Friday, part of what the FBI calls the largest human-trafficking case charged in U.S. history

Los Angeles-based Global Horizons Manpower Inc. CEO Mordechai Orian, 45, surrendered to federal authorities in Honolulu earlier Friday, a day after the FBI had tried to arrest him at his Southern California home but found he wasn’t there.

Three of his employees and two Thailand-based recruiters also were charged in an indictment announced Thursday.