Most of a dozen airport warehouse employees charged with using forged immigration documents to get jobs were given security badges after required federal background checks, but fell under suspicion in the process of renewing their clearances, authorities said Thursday.

State police said 12 employees of Empire Warehouse Solutions at Stewart International Airport were arrested early Thursday and charged with falsifying business records and offering a false instrument for filing.

The workers from Mexico, Peru, Chile, Guatemala and El Salvador used forged Social Security and resident alien cards to get hired, authorities said.

Michael Gourlay, president of the warehouse services company, said his company is a subcontractor of United Parcel Service. He said the 12 employees represent about half of his workers at the Newburgh facility, located near a runway at the airport.

All 12 workers had undergone Transportation Security Administration background checks after Empire Warehouse Solutions got the Newburgh contract in April 2006, Gourlay said.

"We get what appears to be valid IDs, which are required," he said, "and they're all processed through the TSA's national background check. They'd all been approved."

But TSA spokeswoman Ann Davis said only nine of the 12 had security badges issued by the airport as a "trusted agent" of the federal agency. Of the other three, two had badge applications pending and one had his application rejected, she said.

She said the nine workers got badges during or before 2006, when TSA did criminal history and terrorist connection checks, but didn't verify immigration status. Starting in 2007, immigration status has been checked by TSA. She didn't have information on why one of the worker's badges was not approved. The agency requires badge renewals every two years, a process Davis said led to an airport official spotting dubious documentation that touched off the investigation and Thursday's arrests.

Davis also said the badges only allow access to defined areas, in this case the cargo center, and that it's up to companies to properly vet the documents workers produce to prove they're legally entitled to work in the U.S.

State police said the workers didn't pose a threat to air travelers and weren't part of any larger criminal operation.

State Police Maj. Edward Raso said they didn't have access to the New York Air National Guard base across the airport grounds from the warehouse. The Air Guard's 105th Airlift Wing flies C-5A Galaxy cargo planes from the base.

Raso said there could be more arrests as the investigation continues.

The arrested workers were being held in the Orange County Jail on no bail. Authorities said they will be deported.