Electronic account records for some 500,000 banking customers at four different banks were allegedly stolen and sold to collection agencies in a data-theft case that has so far led to criminal charges against nine people, including seven former bank employees.

According to the U.S. Department of the Treasury, the crime is believed to be the largest breach of banking security in the U.S., local police said.

Hackensack, N.J., police Det. Capt. Frank Lomia said the investigation into the crime ring is still under way.

"This thing's getting bigger and bigger," Lomia said. "It's still growing. The banks are uncovering more accounts than we knew about."

The police announced the arrests of the nine suspects on April 28 and charged them with illegally selling personal identification information stolen from bank and New Jersey state computer databases.

The police investigation alleges that a company called DRL Associates Inc. was set up to find individuals and as a collection agency, but was not properly licensed for those activities by the state.

A Hackensack man, Orazio Lembo, 35, has been charged with one count of racketeering and eight counts of disclosing data from a database for his role in the crime ring. Police allege that Lembo used his home as an office for DRL Associates and that he had hired several upper level bank employees to access data, including names, account numbers and balances, from the banks.

The bank employees worked for Wachovia Corp., Bank of America Corp., Commerce Bancorp Inc. and PNC Bank NA. One of the other suspects is a former manager of the New Jersey Department of Labor.