The head of a labor recruiting company accused of exploiting 400 workers from Thailand and forcing them to work on U.S. farms is under arrest.

FBI Special Agent Tom Simon said Los Angeles-based Global Horizons Manpower Inc. CEO Mordechai Orian surrendered Friday at his attorney’s office in Honolulu. The FBI had attempted to arrest Orian at his home in Los Angeles on Thursday.

Orian, three of his employees and two Thailand-based recruiters were charged in an indictment announced Thursday.

The FBI says it is the largest human-trafficking case ever charged in U.S. history.