A Plymouth-based staffing company will pay $250,000 to the federal government under a settlement that arose from a Justice Department investigation uncovering allegations of "routine" discrimination against non-U.S. citizen workers.

The Justice Department said Thursday that Corp IV Holdings Inc., which does business as Masterson Staffing Solutions, discriminated by requiring documents such as green cards from newly hired lawful permanent residents and work permits for other non-U.S. citizens to prove their permission to work in the United States.

Federal law allows workers to choose among legally acceptable documents regardless of their citizenship, immigration status or national origin. Under the law, employers must allow workers to show the acceptable documentation that the workers choose — such as driver's licenses and Social Security cards — and may not unnecessarily re-verify a worker's permission to work.

"When employees present legally acceptable documentation to demonstrate their permission to work, employers cannot demand different or additional documents because of the employees' citizenship or immigration status," said Assistant Attorney General Kristen Clarke of the Justice Department's Civil Rights Division.

A message was left seeking comment on Thursday from Masterson Staffing. The settlement agreement was signed Monday by Bryan Hoerr, the firm's executive vice president of operations, and Thursday by Deputy Special Counsel Alberto Ruisanchez of the Justice Department's Immigrant and Employee Rights Section.

The Justice Department said that at least one person granted asylum lost work because of Masterson Staffing's requirements. It also found that the company often required certain lawful permanent residents to show unnecessary documents to prove their continued permission to work.

In addition to the $250,000 civil penalty that will be paid to the federal government, Masterson Staffing will make $100,000 available for a back pay fund to compensate victims. The company has agreed to train staff on the Immigration and Nationality Act's anti-discrimination provision, modify its policies and be subject to quarterly reporting requirements.

The back pay fund is available to compensate people who can demonstrate that they lost wages or other "compensable economic damages" because of alleged discrimination. Back pay recipients will receive a single payment of $5,144.73.

According to the settlement agreement, the Justice Department told Masterson Staffing that it started an investigation in June 2021.