WASHINGTON -- The Homeland Security Department is proposing that a private company give it access to a nationwide database of license plate tracking information.

The department says in a new contract proposal that the database would be used by Immigration and Customs Enforcement to help track down criminal immigrants or absconders. The contract notice comes amid growing concerns about government surveillance of U.S. citizens, but it doesn't address potential privacy consequences.

ICE spokeswoman Gillian Christensen said Wednesday the database could only be accessed in conjunction with ongoing criminal investigations or to locate wanted individuals.

Privacy advocates worry that letting the government have access to millions of records from license plate readers will let the government track the everyday movements of American citizens who aren't suspected of a crime.