(CNN) -- The federal government is calling a human-trafficking lawsuit against a California-based farm labor contractor the largest case of alleged forced labor of farm workers in the United States.

The lawsuit, made public Tuesday by the U.S. Equal Employment Opportunity Commission, accused Global Horizons Manpower Inc., based in Beverly Hills, California, and eight farms in Hawaii and Washington state of luring more than 200 men from Thailand to work at farms in Hawaii and Washington where they were subjected to abuse.

Global Horizons did not immediately respond to a CNN request for comment.

The lawsuit alleges Global Horizons promised the Thai workers lucrative jobs. But once the men arrived, the suit says, their passports were confiscated and they were not paid for their work. It also alleges they were forced to live in cramped, dirty conditions.

"Upon arriving to the U.S., their passports were confiscated and they were threatened with deportation if they complained," Michael Farrell, an EEOC attorney said Tuesday during a news conference in Honolulu announcing details of the lawsuit.

The lawsuit alleges the workers endured screaming, threats and physical assaults by their supervisors.

"In some cases bodyguards were stationed around the farms to ensure that none of the workers escaped," Farrell told CNN affiliate KHON.

The federal lawsuit accuses Global Horizons and the farms of violating the Civil Rights Act. It is seeking back pay and monetary damages for the workers.