from another source

Some of the detainees had entered the country unlawfully, while others arrived on temporary visas or through a waiver program that does not allow employment, according to Steven Schrank, the lead Georgia agent of Homeland Security Investigations.

Attorney Charles Kuck, who represents two detained workers, told AP his clients arrived under the visa waiver program and were in the country legally for tourism or business. He said one had been in the U.S. for only two weeks and the other for 45 days, both planning to return home soon.

Immigration and Customs Enforcement (ICE) spokesperson Lindsay Williams told AP that some individuals were detained due to prior criminal records and added, "Once citizens have identified themselves, we have no authority" to detain them. Hyundai stated Friday that it believed none of its direct employees were among those detained and said it was reviewing its practices to ensure legal compliance by contractors and subcontractors.