A grocery retailer in Pittsburgh must pay its employees $15,000 in back wages and damages because they refused to pay overtime and threatened coworkers.

Simon’s Food Concessions in Pittsburgh’s Brookline neighborhood denied paying six employees 1.5 times their usual wages for work beyond the usual 40-hour week, according to the U.S. Department of Labor.

The investigators accused the employer of threatening employees because they cooperated with the authorities’ investigations.

The agency said Simon attempted to send a worker on a temporary work visa home before his contract ended.

Simon’s Food Concessions also did not keep accurate records of the number of hours worked by its employees, the federal agency said in a press release on Monday.

Simon’s Food Concessions did not immediately respond to a request for comment.

In September, the department’s attorney’s office sued Ikaros Gourmet Co., a food stand that does business as Simon’s Food Concessions, for several violations of the Fair Labor Standards Act.

In his complaint, owner Simeon Koutoufaris was accused of meeting with Salvadoran employees in the United States who had work visas, and he angrily demanded to know who had contacted the Labor Department.

The complaint alleges that Koutoufaris threatened to fire anyone who did so, told workers he would give them a bad reference if they complained to the government, and that he also singled out one particular worker, fired him, and tried to send him back to El Salvador.

Due to repeated threats, employees became afraid to tell the truth or cooperate with investigators, the department claimed.

The department obtained a temporary restraining order to prevent the employer from further retaliating or obstructing its investigation.

In June, the company was required in a settlement to pay workers about $15,000 in back wages and damages.

“Federal law protects workers’ rights to participate in investigations into a company’s wage practices and prevents employers from retaliating or intimidating those who do,” John DuMont, Pittsburgh district director of the Labor Department’s Wage and Hour Division, said in a statement.

Founded in 1976, Simon’s Food Concessions specializes in catering and food concessions in Pennsylvania and the surrounding areas.

It is owned by Simeon and Tina Koutoufaris. The Labor Department’s lawsuit names Ikaros, Simon’s and Simeon Koutoufaris as defendants.