SEATTLE >> Washington state today sued the operator of one of the largest private immigration detention centers in the United States, claiming thousands of detainees were paid $1 per day for the work they performed but should have received the state’s much higher minimum wage.

State Attorney General Bob Ferguson filed the lawsuit claiming The GEO Group made millions of dollars and profits by illegally exploiting the workers. The Florida-based company owns and operates the Northwest Detention Center in Tacoma under a contract with U.S. Immigration and Customs Enforcement.

Detainees since 2005 did laundry, cooked, cleaned and performed other work but were only paid $1 per day and in some cases did not receive that much because they were paid in food or snacks, the lawsuit said.

“The law is clear. They should have been paid the state’s minimum wage at the time they were working,” Ferguson told reporters in Seattle.

GEO denied the claims, saying the center has a volunteer work program and minimum wages rates and standards specified exclusively by the federal government under standards set for detainees in 2011.

The company in an emailed statement said it “refutes the baseless and meritless allegations made in this lawsuit, and we intend to vigorously defend our company against these claims.”

Ferguson said the 2011 standards required GEO to pay detainees at least $1 day for their labor, but said the company was also required to follow Washington’s minimum wage laws and that detainees that provide labor were protected as “employees.” The state’s minimum wage ranged from $7.35 an hour in 2005 to $11 an hour now.

GEO’s contract with the federal government requires it to comply with state laws, Ferguson added.

The detention center opened in 2004 with 500 beds and now has 1,575, making it the fourth largest immigration detention centers in the U.S., according to Washington state officials. People are held at the center while facing deportation or other immigration proceedings.

The lawsuit seeks a court order for GEO to comply with Washington minimum wage laws and to give up profits that it allegedly made by underpaying detainees. The amount is expected to be millions of dollars, Ferguson said.

Ferguson said state officials would look into whether it would be possible to pay the former detainees back wages if it wins monetary damages in the case, but said it would be challenging to track them down.

State officials will probably ask a judge to put any money awarded into a fund that would support people who are detained at the center and to people in the community near the center who may have been unable to find employment because the detainees were paid less than minimum wage.