SAN DIEGO (CN) — A privately run immigration prison in San Diego forces its inmates to clean their own jail for a dollar a day or less, two prisoners say in a federal class action.

Sylvester Owino and Jonathan Gomez sued CoreCivic, formerly known as Corrections Corporation of America, a Nashville-based corporation that is one of the biggest private prison companies in the country.

In 2016, private prisons such as those run by CoreCivic held almost three-quarters of federal immigration detainees, according to U.S. Immigration and Customs Enforcement.

Nine of the country’s 10 largest immigration jails are operated by private companies.

Critics of private prisons cheered an order by President Barack Obama last year that aimed to phase out the private jails, but the new Attorney General Jeff Sessions reversed that order in February.

The stock price of Corrections Corporation of America increased by 43 percent the day after President Donald Trump was elected, according to The New York Times.

Owino and Gomez say CoreCivic violates labor laws by using them and other prisoners “to clean, maintain and operate” the Otay Mesa Detention Center in San Diego.

“In some instances CoreCivic pays detainees $1 per day, and in other instances detainees are not compensated with wages at all, for their labor and services,” according to the May 31 lawsuit. It adds: “In 2016, CoreCivic reported $1.79 billion in total revenues.”

Among other things, prisoners are ordered to clean the jail, prepare and serve meals, do laundry, cut hair, and run a law library, according to the complaint. And Core Civic threatens detainees with punishment if they refuse to work, according to the complaint.

Owino, who was jailed at Otay Mesa for nearly a decade, says he was made to work at a medical facility without protective equipment.

Gomez, who was jailed there for more than a year, says he worked for a dollar a day in “an unsafe work environment.”

They seek an injunction, the difference between the fair value of their labor and what they were paid, and damages on 12 counts, including forced labor, violations of the Trafficking Victims Protection Act, Labor Code violations, negligence, unjust enrichment and unfair competition.

They also seek certification of a nationwide class of immigration detainees, and two classes of California detainees, who performed unpaid labor, or work for a dollar a day.

“The total number of civil immigration detainees who were subjected to defendant’s forced labor and human trafficking practices, and defendant’s illegal dollar-a-day work practices is currently unknown, but these illegal practices appear endemic to the CoreCivic operations on a California-wide, and indeed a nationwide, scale,” the complaint states.

“However, CoreCivic can provide the information regarding how many civil immigration detainees were subjected to these illegal practices through its solitary confinement and detention logs and also through its business records.”

The plaintiffs are represented by Robert L. Teel in Langley, Washington.

A spokesperson for CoreCivic declined to comment on the lawsuit, but said that “all work programs at our ICE detention facilities are completely voluntary and operated in full compliance with ICE standards.”

According to the Detention Watch coalition, U.S. immigration prisons hold about 400,000 people a year. The group has filed Freedom of Information Act requests about bed quotas at immigration jails for more than three years. CoreCivic has vigorously fought against disclosure, claiming it could expose trade secrets. Many human rights advocates say the federal government privatized its immigration prisons to shield its own abuses from scrutiny. Unlike private, profit-seeking companies such as CCA/Core Civic, the federal government cannot duck FOIA requests by claiming trade secret exemptions.

In April this year, the Second Circuit denied CoreCivic’s and Geo Group’s attempt to block the disclosure of the bed quota information requested. They are the nation’s two largest private prison corporations.

In March, the widow of a man who was jailed at Otay Mesa sued CoreCivic and the U.S. government after he died of complications from pneumonia. She claims jail workers ignored his requests for medical care.