About 800 out of 1,200 former employees who had been laid off at U.S. Investigative Services last month at Grove City and Boyers have already been hired by another company to do similar work.

Since Wednesday, NT Concepts has hired 800 workers to do support services at Iron Mountain in Boyers.

“There’s been quite a bit of activity in these past few days,” said Susan Forbes, an NT Concepts representative. “We are providing on behalf of the (U.S. Office of Personnel Management) support services rather than the field investigative services.”

She added there are plans to hire an additional 150 to 200 workers in the next month.

NT Concepts, with its headquarters in Vienna, Va., provides investigative services, program management, consulting and training.

KeyPoint Government Solutions, which is based in Loveland, Colo., and has offices in Slippery Rock and Grove City, also has employees who do similar work. Phone calls to KeyPoint representatives were not immediately returned.

USIS, which has offices in Boyers and Grove City, announced that the termination of two federal government contracts last week meant about 2,500 of its employees across the United States would lose their jobs.

Those layoffs included the three offices in Boyers and Grove City that had employed 1,500 people. The company, based in Falls Church, Va., had 6,000 employees.

In September, the federal Office of Personnel Management announced it would not renew its contracts with the company, which were to do background checks for prospective federal employees.

This came on the heels of USIS discovering an external cyber attack on its corporate network in August and having a federal complaint filed against it in January. The complaint alleged the company at its Grove City and Boyers offices did at least 665,000 incomplete background checks for OPM between 2008 and 2012.

Last week, Thomas Karaniewsky, a former employee at the Grove City office of USIS, filed a federal class action lawsuit against USIS, alleging he and other workers were terminated without 60 days of advance written notice. He is seeking to recover 60 days of wages and benefits.

According to the lawsuit filed in Pittsburgh, Karaniewsky and other employees at the Grove City office were relieved of their duties without pay Aug. 7, which the company called a furlough. He received a termination letter Sept. 24 stating he would be terminated effective Sept. 30.

The lawsuit said 1,200 employees in the area were terminated without notice Aug. 7.