A class-action lawsuit filed Tuesday in Georgia accuses the country’s largest private prison contractor of forcing detained immigrants to work for between $1 and $8 dollars per day, in violation of the federal minimum wage law.  The civil lawsuit, filed in federal court on behalf of three immigrants detained at CoreCivic’s Stewart Detention Center in Lumpkin, Georgia, says that those who decline to participate in the voluntary work scheme face threats of retaliation, including criminal prosecution.  The lawsuit was jointly filed by the Southern Poverty Law Center, Project South and the law offices of Andrew Free and Burns Charest...The lawsuit marks the latest attempt to challenge the legality of obliging immigrants to work while detained for wages that fall well below the federal minimum wage...Obliging detainees to work for such low wages subsidizes CoreCivic, which should either pay minimum wage or look to the local labor market for employees if detainees refuse to work, the lawsuit adds...CoreCivic spokesman Jonathan Burns said that the company does not comment on pending litigation as a matter of policy.  He added that “all work programs at our ICE detention facilities are completely voluntary and operated in full compliance with ICE standards, including federally mandated statutory reimbursement rates for Voluntary Work Program participants.”...Detainees at CoreCivi’s remote detention center commonly work in the kitchen or carry out cleaning or custodial work, for which they earn approximately $1 per hour...