PHOENIX (AP) - Authorities fear the booming industry of identity theft in Arizona is about to get even bigger as some illegal immigrants look for ways to circumvent the state's new employer-sanctions law and a new Bush administration policy.

Hundreds of operations in the Phoenix metro area churn out fake green cards, Social Security cards and driver's licenses, and authorities say illegal immigrants are the chief customers.

But the new employer-sanctions law, which prohibits employers from knowingly hiring illegal immigrants and takes effect in January, is anticipated to increase the demand for fake documents, especially those that use authentic numbers.

That would then create a need for more identity theft in Arizona, already the state with the highest identity-theft rate in the nation.

"There is a good potential for an increase in identity theft and also an increase in the manufacture and sale of fraudulent documents," said Leesa Berens Morrison, director of the Arizona Department of Homeland Security.

The new state law requires employers to verify the employment eligibility of their workers through a federal database, but the database can't flag documents made with stolen identities.

Authorities say they expect to not only see a rise in identity theft as a result, but that they'll also see producers of fake documents morphing into large-scale criminal enterprises producing high-quality fraudulent documents made with real names and real Social Security numbers stolen from someone else. Currently, they say most producers now are small rings that use invented ID numbers that belong to no one.

"The days of the mom-and-pop forgers are probably over," Arizona Attorney General Terry Goddard said.

Also adding to the anticipated demand are new rules announced last week by the Bush administration. Under those rules, employers risk prosecution if they don't fire workers whose names and Social Security numbers don't match.

Law-enforcement officials believe most illegal immigrants own fake documents or can easily obtain them. The documents are used for air travel, vehicle registration, bank accounts and check cashing.

But authorities say illegal immigrants mainly use them to get jobs.

"These documents are not being constructed to fool an immigration officer, a Border Patrol officer or any person at a port of entry," said Jeffrey Ellis, a senior special agent with the Tucson office of U.S. Immigration and Customs Enforcement. "The desire to be employed is driving the train."

Authorities say customers can buy a fake green card and a Social Security card for as little as $70 on the street. Add a driver's license, and they can cost between $140 and $160.

Those prices buy documents with randomly generated numbers.

Buying fake documents made with government-issued ID numbers and a matching name stolen from someone else costs three to five times more.