JACKSON, Miss. (AP) — Forty-four farms in Mississippi exploited local Black workers by paying higher wages to immigrants who were in the United States on temporary work visas, the U.S. Labor Department said Wednesday.

The department announced it completed investigations that it began last year in the rural flatlands of the Mississippi Delta, one of the poorest areas of the U.S.

The 44 farms include catfish growers and operations that raise crops such as rice, soybeans and corn. They have paid $505,540 in back wages for 161 workers, plus $341,838 in civil penalties, the department said.

“The outcome of these investigations confirms that employers in the Mississippi Delta denied a large number of marginalized farmworkers their lawful wages, and in some cases, violated the rights of U.S. workers by giving temporary guest workers preferential treatment,” said Audrey Hall, district director of the Wage and Hour Division in Jackson, Mississippi.

The Labor Department announced its findings six months after two agriculture businesses in the Delta settled lawsuits filed on behalf of local Black farmworkers over claims that farms hired white laborers from South Africa and paid them more than the local Black employees for the same type of work.

The Labor Department said Wednesday that its investigations found employers violated several requirements of the H-2A visa program, including by failing to pay the required wages to U.S. workers in jobs similar to those held by immigrants.