Cree, a pioneer of silicon carbide devices and integrated circuits, has government and military contracts worth $153 million, the report said.

Of the 35 people detained by the U.S. Immigation and Customs Enforcement Service, eight people worked for Cree and the others were employed by two Cree subcontractors. Those arrested were from the Congo, Gambia, Ghana, Guatemala, Indonesia, Israel, Kenya, Mexico, Pakistan and Togo, the report said.

The report referenced unnamed officials saying the workers performed janitorial and manufacturing jobs in a high-security area.

The report cited Tom O'Connell, the agent in charge for Raleigh, N.C., as saying that Cree cooperated with the agency. “Unauthorized workers pose potential homeland security threats. Not only is their identity in question, they may also be vulnerable to exploitation by terrorists and other criminals,” the report quoted O’Connell as saying.

Immigration agents have been targeting military bases and airports and are now looking at companies with military contracts, the report said.

Cree was awarded a $15 million contract to advance silicon carbide microwave technology under a program administered by the U.S. Air Force Research Laboratory in September.

Under the five-year contract, Cree is being paid to advance silicon carbide (SiC) microwave monolithic integrated circuit (MMIC) processing techniques to transition the production of SiC MMICs to 100-mm substrates and reduce cost per chip.