KANSAS CITY, Mo. — A huge human trafficking ring based in Kansas City allegedly lured hundreds of foreign workers into low-paying jobs illegally and turned them into "modern-day slaves," federal officials announced Wednesday.

Three area employment firms controlled by a suburban Mission, Kan., resident brought the workers into the United States and forced them to live in substandard conditions, Wednesday's indictment alleged.

Occasionally cramming eight workers into a small apartment and making some sleep on the floor or on air mattresses, the employment companies provided the workers under contract to construction firms and hotels, resorts and casinos in 14 states.

Those construction businesses and hotels were assured that their contract workers were being paid prevailing wages. But the employment firms allegedly paid the workers only a fraction of what they deserved and heaped on thousands of dollars in fees, making it impossible for them to quit or even afford a plane ticket home.

"The indictment alleges that this criminal enterprise lured victims to the United States under the guise of legitimate jobs and a better life, only to treat them as modern-day slaves under the threat of deportation," said James Gibbons, acting special agent in charge of U.S. Immigration and Customs Enforcement, in a written statement.

Wednesday's federal indictment accused 12 people and the three companies of racketeering, visa fraud, marriage fraud, identity theft and other counts in a scheme that allegedly involved forced labor trafficking and immigration violations. The conspiracy allegedly started in 2001.

The grand jury returned the 90-page, 45-count indictment in secret on May 6. Prosecutors announced it Wednesday after authorities arrested eight defendants the day before. Don Ledford, a spokesman for the U.S. attorney's office, said investigators still were serving search warrants Wednesday and had begun interviewing some of the workers.

If a worker is determined to be a victim of human trafficking, he or she would become eligible for federal medical, counseling, food and housing services, Ledford said. Human trafficking victims also may apply to remain in the United States legally.

Most of the workers came from Jamaica, the Dominican Republic and the Philippines, Ledford said.

The enterprise — based out of companies headquartered in Kansas City, Mission and Overland Park, Kan. — allegedly employed hundreds of illegal aliens as construction workers and as cleaners and housekeepers at hotels, resorts and casinos in Missouri, Kansas, Alabama, Arizona, California, Colorado, Florida, Louisiana, Massachusetts, Minnesota, Nevada, New Jersey, South Carolina and Wyoming.